Thorax Anatomy-Thoracic wall(Snell's Clinical Anatomy By Regions 10th Edition) Flashcards

Question

Enumerate the structures the manubrium articulates with?

Answer 1

(1)Body of the sternum-at the manubriosternal joint (2)Clavicle (3)On each side:1.1st costal cartilage 2.upper part of the 2nd costal cartilage

Answer 2

(I)Suprasternal(jugular)notch .location:1)on the superior border of the sternum 2)It lies opposite the lower border of the body of T2 .features:1)easily palpable-easily felt between the prominent medial ends of the clavicles in the midline. 2)concave notch (II)Clavicular notch .location:1)at each suprapleural corner of the manubrium 2)on each side of the jugular notch .shape:is an ovoid articular surface .function:each holds the sternal end of clavicle

Answer 3

.location:1)on the superior border of the sternum 2)It lies opposite the lower border of the body of T2 .features:1)easily palpable-easily felt between the prominent medial ends of the clavicles in the midline. 2)concave notch

Answer 4

1)on the superior border of the sternum 2)It lies opposite the lower border of the body of T2

Answer 5

1)easily palpable-easily felt between the prominent medial ends of the clavicles in the midline. 2)concave notch

Answer 6

.location:1)at each suprapleural corner of the manubrium 2)on each side of the jugular notch .shape:is an ovoid articular surface .function:each holds the sternal end of clavicle

Answer 7

1)at each suprapleural corner of the manubrium 2)on each side of the jugular notch

Answer 8

Is an ovoid articular surface

Answer 9

Each holds the sternal end of a clavicle

Answer 10

Is the relatively long,middle part of the sternum

Answer 11

(I)Above-Manubriosternal joint (sternal angle or angle of Louis) (2)Below-xiphisternal joint (3)On each side-The body of the sternum articulates with the 2nd to 7th costal cartilages on each side.

Answer 12

The body of the sternum articulates above with the manubrium at the manubriosternal joint (or manubriosternal angle or sternal angle or angle of Louis)

Answer 13

The sternal angle can be recognised by the presence of a transverse ridge on the anterior aspect of the sternum.

Answer 14

Between the manubrium and the body of the sternum

Answer 15

Is a cartilaginous joint

Answer 16

A small amount of angular movement is possible here.

Answer 17

The manubriosternal joint (sternal angle or angle of Louis)is an important landmark for thoracic anatomy because it marks(i.e,structures at the level of manubriosternal joint or also called sternal angle or angle of Louis)the following:- (1)The manubriosternal joint (symphyseal joint). (2)The attachment points of the 2nd costal cartilages of the 2nd ribs(thus these attach to both manubrium and body). (3)A horizontal line that typically projects posteriorly onto T4 intervertebral disc(or in another words,the lower border of T4 or the intervertebral disc between T4 and and T5). (4)The plane of separation (i.e.,transition point)between the superior and inferior medistina. (5)Arch of the aorta (6)Tracheal bifurcation (7)Union of the azygos vein and superior vena cava(SVC). (8)The thoracic duct crosses to the midline. (9)Pulmonary trunk (10)Ligamentum arteriosum (11)Nerves:1.cardiac plexus 2.left recurrent laryngeal nerve

Answer 18

1)Manubriosternal angle 2)Sternal angle 3)Angle of Louis

Answer 19

Counting the ribs:- (1)The position of the sternal angle can easily be felt and is often seen as a transverse ridge. (2)The finger moved to the right or to the left will pass directly onto the 2nd costal cartilage and then the 2nd rib. (3)All ribs may be counted from this point. (4)Occasionally in a very muscular male,large pectoral muscles may obscure the ribs and intercostal spaces.In this case it may be easier to count up from the 12th rib.

Answer 20

.definition:Is the joint between the xiphoid process of the sternum and the body of the sternum. .Formation:The body of the sternum articulates below with the xiphoid process at the xiphisternal joint. .Location(vertebral level):(1)The xiphisternal joint lies opposite the body of T9. (2)Between the xiphoid process and the body of the sternum. (3)The xiphoid process usually fuses with the body of of the sternum during middle age.

Answer 21

Is the joint between the xiphoid process of the sternum and the body of the sternum.

Answer 22

The body of the sternum articulates below with the xiphoid process at the xiphisternal joint.

Answer 23

(1)The xiphisternal joint lies opposite the body of T9. (2)Between the xiphoid process and the body of sternum. (3)The xiphoid process usually fuses with the body of the sternum during middle age.

Answer 24

The body of the sternum articulates with the 2nd to 7th costal cartilages on each side.

Answer 25

.Features:1.small 2.pointed(at its inferior end) 3.Thin plate-It is a thin plate of cartilage that becomes ossified at its proximal end during adult life. 4.It is highly variable in size,shape and degree of ossification .Location:It is the most inferior part of the sternum. .Joint:1.No ribs or costal cartilages attach to the xiphoid process. 2.However,the 7th costal cartilage may have a shared attachment with the xiphoid process and the body.

Answer 26

1.small 2.pointed(at its inferior end) 3.Thin plate-It is a thin plate of cartilage that becomes ossified at its proximal end during adult life. 4.It is highly variable in size,shape and degree of ossification

Answer 27

It is the most inferior part of the sternum.

Answer 28

1.No ribs or costal cartilages attach to the xiphoid process. 2.However,the 7th costal cartilage may have a shared attachment with the xiphoid process and the body.

Answer 29

(1)Subcutaneous (2)Readily palpable along its entire length

Answer 30

(1)Like the ribs,it consists largely of highly vascular cancellous bone enclosed by a thin shell of compact bone. (2)It possesses red haematopoitic marrow throughout life.

Answer 31

.Indication:For aspiration of red marrow .Technique:(1)Because of its morphology and shallow depth in the chest,the sternum can be punctured readily in a needle biopsy procedure(sternal puncture)for aspiration of red marrow. (2)Under a local anaesthetic(LA),a wide bore needle is inserted into the marrow cavity through the anterior surface of the bone.

Answer 32

For aspiration of red marrow

Answer 33

(1)Because of its morphology and shallow depth in the chest,the sternum can be punctured readily in a needle biopsy procedure(sternal puncture)for aspiration of red marrow (2)Under a local anaesthetic(LA),a wide bore needle is inserted into the marrow cavity through the anterior surface of the bone.

Answer 34

The sternum may also be split in surgery to allow the surgeon to gain access to the:- 1.heart 2.great vessels 3.thymus

Answer 35

The sternum Is a resilient structure that Is held In position by relatively pliable costal cartilages and bendable ribs. For these reasons, fracture of the sternum is not common; however, It does occur tn high-speed motor vehicle accidents. Remember that the heart lies posterior to the sternum and may be severely contused by the sternum on impact.

Answer 36

1st /postnatally (A)The adult sternum consists of three parts: manubrium, body, and xiphoid process. (B)The three main parts were named after the resemblance of the sternum to the short sword favored by Roman troops and gladiators-thus, the manubrium(= handle), the body (in older terminol- ogy =gladiolus =small sword), and the xiphoid process (=sword point) 2nd/Prenatally-It consists of six main parts: (A)The first and last parts-remain distinguishable as the manubrium and xiphoid process, respectively. (B)The middle four parts (sterne- brae)-fuse to form the body.

Answer 37

(A)The adult sternum consists of three parts: manubrium, body, and xiphoid process. (B)The three main parts were named after the resemblance of the sternum to the short sword favored by Roman troops and gladiators-thus, the manubrium(= handle), the body (in older terminol- ogy =gladiolus =small sword), and the xiphoid process (=sword point)

Answer 38

It consists of six main parts: (A)The first and last parts-remain distinguishable as the manubrium and xiphoid process, respectively. (B)The middle four parts (sterne- brae)-fuse to form the body.

Answer 39

Cost-is Latin for ribs

Answer 40

Mnemonic:EFAF (1)Elongate (2)Flattened (3)Arched bone (4)Forming a large part of the thoracic wall

Answer 41

The ribs consist largely of a highly vascular cancellous bone enclosed by a thin shell of compact bone.

Answer 42

Normally,both males and females have 12 pairs of ribs

Answer 43

I)Head or posterior(dorsal,vertebral)end of each rib: -Has two facets for articulation with the numerically corresponding vertebral body and that of the vertebra immediately above. -Articulates with one or two thoracic vertebrae. II)The anterior(ventral;sternal)ends: -Have variable relations that allow the ribs to be categorised as 1.True ribs 2.False ribs 3.Floating ribs -The anterior end of each rib is attached to the corresponding costal cartilage. -Is flat and has a depression for the costal cartilage

Answer 44

I)True ribs(pairs 1 to 7)-are connected directly to the sternum via individual costal cartilages II)False ribs(pairs 8 to 10)-are connected to the sternum via individual costal cartilages that join together and attach collectively to the 7th costal cartilages. III)Floating ribs(pairs 11 to 12)-do not attach to the sternum

Answer 45

Are connected directly to the sternum via individual costal cartilages

Answer 46

Pairs 1 to 7

Answer 47

Are connected to the sternum via individual costal cartilages that join together and attach collectively to the 7th costal cartilages.

Answer 48

Pairs 8 to 10

Answer 49

Do not attach to the sternum

Answer 50

Pairs 11 to 12

Answer 51

(1)All the ribs share a common structural floor plan (2)Long (3)Twisted (4)Flat bone

Answer 52

(1)Borders (2)Ends (3)Head or posterior(dorsal;vertebral)end of each rib (4)Neck (5)Tubercle (6)Body(shaft) (7)Costal groove (8)Angle

Answer 53

I)Superior border:(1)Rounded (2)Smooth II)Inferior border:Thin

Answer 54

(1)Rounded (2)Smooth

Answer 55

I)Head or posterior(dorsal,vertebral)end of each rib: -Has two facets for articulation with the numerically corresponding vertebral body and that of the vertebra immediately above. -Articulates with one or two thoracic vertebrae. II)The anterior(ventral;sternal)ends: -Have variable relations that allow the ribs to be categorised as 1.True ribs 2.False ribs 3.Floating ribs -The anterior end of each rib is attached to the corresponding costal cartilage. -Is flat and has a depression for the costal cartilage.

Answer 56

-Has two facets for articulation with the numerically corresponding vertebral body and that of the vertebra immediately above. -Articulates with one or two thoracic vertebrae.

Answer 57

The anterior(ventral;sternal)ends: -Have variable relations that allow the ribs to be categorised as: 1.True ribs 2.False ribs 3.Floating ribs -The anterior end of each rib is attached to the corresponding costal cartilage. -Is flat and has a depression for the costal cartilage

Answer 58

.Location:Situated between the head and the tubercle .Features:(1)Flattened (2)Slightly constricted portion

Answer 59

Situated between the head and the tubercle

Answer 60

(1)Flattened (2)Slightly constricted

Answer 61

.Definition:Is a prominence .Location:(1)On the outer posterior surface of the rib (2)At the junction of the neck with the body .Feature:It has a facet for articulation with the transverse process of the numerically corresponding vertebra

Answer 62

Is a prominence

Answer 63

(1)On the outer surface of the rib (2)At the junction of the neck with the body

Answer 64

It has a facet for articulation with the transverse process of the numerically corresponding vertebra

Answer 65

.Location:Extends from the tubercle to the anterior(sternal)end .Features:(1)Long (2)Thin (3)Flattened (4)Twisted part(on its long axis)

Answer 66

Extends from the tubercle to the anterior(sternal)end

Answer 67

(1)Long (2)Thin (3)Flattened (4)Twisted part(on its long axis)

Answer 68

.Definition:Is the elongate depression .Location:Along the inferior aspect of the internal surface of the shaft of the rib. .Function:This holds the intercostal vessels and nerve

Answer 69

Is the elongate depression

Answer 70

Along the inferior aspect of the internal surface of the shaft of the rib.

Answer 71

This holds the intercostal vessels and nerve

Answer 72

.Definition:Is the point at which the body of the rib bends sharply and turns from a lateral to a more anteriorly directed orientation .Location:Usually slightly distal to the tubercle

Answer 73

Is the point at which the body of the rib bends sharply and turns from a lateral to a more anteriorly directed orientation

Answer 74

Usually slightly distal to the tubercle

Answer 75

.Features:The 1st rib is small and flattened from above downward .Relations:I)The scalenus anterior muscle is attached to its:(1)Upper surface (2)Inner border. II)The subclavian vein anterior to the scalenus anterior,the subclavian vein crosses the rib III)The subclavian artery and the lower trunk of the brachial plexus (1)The brachial plexus of nerves (C5 to 8 and Tl) and the subclavian artery and vein are closely related to the upper surface of the first rib and the clavicle as they enter the upper limb. (2)Posterior to the muscle attachment,the subclavian artery and the lower trunk of the brachial plexus cross the rib and lie in contact with the bone. (3)At the level of the 1st rib,the lower cervical nerve roots combine to form the 3 trunks of the brachial plexus.The lowest trunk is formed by the union of C8 and T1,and this trunk lies directly posterior to the artery and is in contact with the superior surface of the 1st rib. IV)Sibson’s fascia(suprapleural membrane): (1)Attached to the inner margin of the 1st rib and C7. (2)Covers the apex of the lung. .Clinical importance:The 1st rib is important clinically because its close relationship to: (1)The lower nerves of the brachial plexus (2)The main vessels to the arm,namely,the subclavian artery and vein.

Answer 76

Is small and flattened from above downward

Answer 77

I)The scalenus anterior muscle is attached to its:(1)Upper surface (2)Inner border. II)The subclavian vein anterior to the scalenus anterior,the subclavian vein crosses the rib III)The subclavian artery and the lower trunk of the brachial plexus (1)The brachial plexus of nerves (C5 to 8 and Tl) and the subclavian artery and vein are closely related to the upper surface of the first rib and the clavicle as they enter the upper limb. (2)Posterior to the muscle attachment,the subclavian artery and the lower trunk of the brachial plexus cross the rib and lie in contact with the bone. (3)At the level of the 1st rib,the lower cervical nerve roots combine to form the 3 trunks of the brachial plexus.The lowest trunk is formed by the union of C8 and T1,and this trunk lies directly posterior to the artery and is in contact with the superior surface of the 1st rib. IV)Sibson’s fascia(suprapleural membrane): (1)Attached to the inner margin of the 1st rib and C7. (2)Covers the apex of the lung.

Answer 78

The 1st rib is important clinically because its close relationship to: (1)The lower nerves of the brachial plexus (2)The main vessels to the arm,namely,the subclavian artery and vein.

Answer 79

.Definition:It is usually a fibrous band that attaches to the 1st thoracic rib. .Location:A rib arising from the anterior tubercle of the transverse process of the seventh cervical vertebra .Incidence:Occurs in about 0.2-0.4%(or 0.5%)in humans .Aetiology:I)Cervical ribs occur as a result the elongation of the transverse process of the 7th cervical vertebra. II)Congenital cases-may present around the 3rd decade III)Trauma .Structure:I)Consist of an anomalous fibrous band -that often originates from C7 -may arc towards the sternum -rarely reaches the sternum II)It may have a free anterior end,may be connected to the 1st rib by a fibrous band. III)May articulates with the 1st rib .C/P:I)Bilateral in up to 70% II)Neurological symptoms -In most cases -It may cause pressure on the lower trunk of the brachial plexus,causing: (1)Pain down the medial side of the forearm and hand. (2) Wasting of the small muscles of the hand. III)Compression of the subclavian artery(absent radial pulse on clinical examination) -It can also exert pressure on the overlying subclavian artery and interfere with the circulation of the upper limb. -Positive Adsons test(lateral flexion of the neck towards the symptomatic side and traction of the symptomatic arm-leads to obliteration of the radial pulse). .Treatment:I)Indication When there is evidence of neurovascular compromise II)Method A transaxillary approach-is the traditional operative method for excision

Answer 80

It is usually a fibrous band that attaches to the 1st thoracic rib.

Answer 81

A rib arising from the anterior tubercle of the transverse process of the seventh cervical vertebra(C7)

Answer 82

Occurs in about 0.2-0.4%(or 0.5%)in humans .

Answer 83

I)Cervical ribs occur as a result the elongation of the transverse process of the 7th cervical vertebra. II)Congenital cases-may present around the 3rd decade III)Trauma

Answer 84

I)Consist of an anomalous fibrous band -that often originates from C7 -may arc towards the sternum -rarely reaches the sternum II)It may have a free anterior end,may be connected to the 1st rib by a fibrous band. III)May articulates with the 1st rib

Answer 85

To gain entrance to the thoracic cavity, thoracic surgeons commonly perform a rib excision. A longitudinal incision is made through the periosteum on the outer surface of the rib, and a segment of the rib is removed. A second longitudinal incision is then made through the bed of the rib, which is the inner covering of the periosteum. After the operation, the rib regenerates from the osteogenetic layer of the periosteum.

Answer 86

Bruising of a rib, secondary to trauma, is the most common rib Injury. In this painful condition, a small hemorrhage occurs beneath the periosteum.

Answer 87

.Incidence:I)In general-Common Fractures of the rib are common chest injuries. II)In children-Rare In children the ribs are highly elastic,and fractures in this age group are therefore rare. III)In the young-More common -Unfortunately,the pliable chest wall in the young can be easily compressed so that the underlying lungs and heart may be Injured. -With increasing age,the rib cage becomes more rigid owing to deposit of calcium in the costal cartilages,and the ribs become brittle.The ribs then tend to break at their weakest part ,their angles. .Risk factor:The ribs prone to the fracture are those that are exposed or relatively fixed. .Sites:I)The 1st 4 ribs (1)Anteriorly-The clavicle and pectoral muscles protect the 1st 4 ribs (2)Posteriorly-The scapula and its associated muscles protect the 1st 4 ribs. II)The ribs 5 through 10 Are the most commonly fractured ribs. III)The 11th and 12th ribs Floating and move with the force of impact .C/P:I)Pneumothorax Because the ribs is sandwiched between the skin externally and the delicate pleura internally, not surprisingly, the jagged ends of a fractured rib may penetrate the lungs and present as a pneumothorax. II)Severe localised intercostal pain -Is usually the most important symptom of a fractured rib -The intercostal nerves above and below the rib innervate the periosteum of each rib. -To encourage the patient to breathe adequately, performing an intercostal nerve block may be necessary to relieve the pain.

Answer 88

.Definition:Are bars of cartilage .Function:I)Connecting the: (1)Upper 7 ribs to the lateral edge of the sternum (2)8th,9th,and 10th ribs to the cartilage immediately above II)The cartilages of the 11th and 12th ribs end in the abdominal musculature III)The costal cartilages contribute significantly to the elasticity and mobility of the thoracic walls. .Clinical importance:In old age,the costal cartilages tend to lose some of their flexibility as the result of superficial calcification.

Answer 89

Are bars of cartilage

Answer 90

I)Connecting the: (1)Upper 7 ribs to the lateral edge of the sternum (2)8th,9th,and 10th ribs to the cartilage immediately above II)The cartilages of the 11th and 12th ribs end in the abdominal musculature III)The costal cartilages contribute significantly to the elasticity and mobility of the thoracic walls.

Answer 91

In old age,the costal cartilages tend to lose some of their flexibility as the result of superficial calcification.

Answer 92

The body of the sternum articulates with the 2nd to 7th costal cartilages on each side.

Answer 93

The shape of the thorax can be distorted by:- I)Congenital anomalies of the vertebral column II)By the ribs III)Destructive disease of the vertebral column -produces lateral flexion or scoliosis -results in marked distortion of the thoracic cage

Answer 94

Traumatic Injury to the thorax is common, especially as a result of automobile accidents.

Answer 95

.Definition:A number of ribs may break,in which a section of the chest wall is disconnected from the rest of the thoracic wall. .Aetiology:Severe crush injuries .Site:I)If limited to one side the fractures may occur (1)Near the rib angle (2)Anteriorly near the costochondoral junction II)If the fractures occur on either side of the sternum The sternum may be flail .Mechanism:I)The stability of the chest wall is lost II)During inspiration-the flail segment is sucked in III)During expiration-the falil segment is driven out IV)This produces paradoxical and ineffective respiratory movements

Answer 96

A number of ribs may break,in which a section of the chest wall is disconnected from the rest of the thoracic wall.

Answer 97

Severe crush injuries

Answer 98

I)If limited to one side the fractures may occur (1)Near the rib angle (2)Anteriorly near the costochondoral junction II)If the fractures occur on either side of the sternum The sternum may be flail

Answer 99

I)The stability of the chest wall is lost II)During inspiration-the flail segment is sucked in III)During expiration-the falil segment is driven out IV)This produces paradoxical and ineffective respiratory movements

Answer 100

The vertebral column forms the posterior midline wall of the chest. In severe posterior chest Injuries, the possibility of a vertebral fracture with associated Injury to the spinal cord should be considered. Remember also the presence of the scapula, which overlies the upper seven ribs. This bone is covered with muscles and is fractured only in cases of severe trauma.

Answer 101

Recognising that the upper abdominal organs-namely, the liver, stomach, and spleen-may be injured by trauma to the rib cage is important. In fact, any injury to the chest below the level of the nipple line may involve abdominal organs as well as thoracic organs.

Answer 102

Normally, only the thoracic vertebrae carry ribs, and these vertebrae have unique structures for that purpose.

Answer 103

Facet is Latin for little face

Answer 104

are small articular surfaces

Answer 105

I)At approximately the posterolateral aspect II)At the junction of the body and the pedicle

Answer 106

I)Typical thoracic vertebrae(2 to 8) +Have 2 on each side:(1)Superior costal facet-Located superiorly. (2)Inferior costal facet-Located inferiorly. +These are the sites where the heads of the ribs articulate with the body (i.e., adjacent typical thoracic vertebrae,2 to 8,share the articulation of ribs). +Thus,the head of an individual rib articulates with both the superior costal facet of the numerically corresponding vertebral body and the inferior costal facet of the vertebra immediately above. II)The T1 vertebra +Has a full costal facet(instead of a superior demifacet)for the head of the 1st rib. +Plus an inferior demifacet for the superior half of the head of the 2nd rib. (Think about these directional terms). III)The T11 and T12 vertebrae Each have full costal facets(located mainly on the pedicels)instead of demifacet because the heads of ribs 11 and 12 articulate only with their own individual vertebrae

Answer 107

+Have 2 on each side:(1)Superior costal facet-Located superiorly. (2)Inferior costal facet-Located inferiorly. +These are the sites where the heads of the ribs articulate with the body (i.e., adjacent typical thoracic vertebrae,2 to 8,share the articulation of ribs). +Thus,the head of an individual rib articulates with both (1) the superior costal facet of the numerically corresponding vertebral body and (2) the inferior costal facet of the vertebra immediately above.

Answer 108

+Has a full costal facet(instead of a superior demifacet)for the head of the1st rib. +Plus an inferior demifacet for the superior half of the head of the 2nd rib. (Think about these directional terms).

Answer 109

Demi- is French for "half"

Answer 110

Because each of these facets carries half of the rib articulation, each is commonly termed a demifacet

Answer 111

.Definition:are small articular surfaces on the transverse processes. .Function:I)These are the sites where the tubercle of each rib articulates with the transverse process. II)Usually, these are not present on the Tll and Tl2 vertebrae because ribs 11 and 12 do not articulate with the transverse processes.

Answer 112

are small articular surfaces on the transverse processes.

Answer 113

I)These are the sites where the tubercle of each rib articulates with the transverse process. II)Usually, these are not present on the T11 and Tl2 vertebrae because ribs 11 and 12 do not articulate with the transverse processes.

Answer 114

The vertebral column forms the posterior midline wall of the chest. In severe posterior chest Injuries, the possibility of a vertebral fracture with associated Injury to the spinal cord should be considered. Remember also the presence of the scapula, which overlies the upper seven ribs. This bone is covered with muscles and is fractured only in cases of severe trauma.

Answer 115

Recognising that the upper abdominal organs-namely, the liver, stomach, and spleen-may be injured by trauma to the rib cage is important. In fact, any injury to the chest below the level of the nipple line may involve abdominal organs as well as thoracic organs.

Answer 116

I)The first rib and the 3 lowest ribs(i.e.,ribs 10,11,12) have a single synovial joint with their corresponding vertebral body. II)For the second to ninth ribs the head articulates by means of a synovial joint with the corresponding vertebral body and that of the vertebra above it. III)Astrong intra-articular ligament connects the head to the inter- vertebral disc.

Answer 117

I)have a single synovial joint with their corresponding vertebral body. II)Astrong intra-articular ligament connects the head to the inter- vertebral disc.

Answer 118

I)the head articulates by means of a synovial joint with the corresponding vertebral body and that of the vertebra above it. II)Astrong intra-articular ligament connects the head to the inter- vertebral disc.

Answer 119

I)The tubercle of a rib articulates by means of a synovial joint with the transverse process of the corresponding vertebra. II)This joint is absent on the 11th and 12th ribs.

Answer 120

These joints are cartilaginous joints. No movement is possible here.

Answer 121

I)The first costal cartilages articulate with the manubrium by cartilaginous joints that do not permit movement. II)The second to seventh costal cartilages articulate with the lateral border of the sternum by synovial joints. III)In addition, the 6th, 7th, 8th, 9th, and l0th costal cartilages articulate with one another along their borders by small synovial joints. IV)The cartilages of the 11th and 12th ribs do not articulate with the sternum and are embedded in the abdominal musculature.

Answer 122

I)The first ribs and their costal cartilages are fixed to the manubrium and are immobile. II)The raising and lowering of the ribs during respiration are accompanied by movements in both the joints of the head and the tubercle, permitting the neck of each rib to rotate around Its own axis.

Answer 123

.Definition:Numerous gaps connect the thorax with other regions and/or separate the bones of the thoracic cage from one another. .Types:I)Relatively large apertures-occur at the upper and lower limits of the thorax. II)relatively narrow and elongate Intercostal spaces-separate adjacent ribs.

Answer 124

Numerous gaps connect the thorax with other regions and/or separate the bones of the thoracic cage from one another.

Answer 125

I)Relatively large apertures-(1)Superior thoracic aperture or thoracic outlet occur at the upper limits of the thorax. (2)Inferior thoracic aperture or thoracic inlet. occur at the lower limits of the thorax II)Relatively narrow and elongate Intercostal spaces-separate adjacent ribs.

Answer 126

(1)Superior thoracic aperture or thoracic outlet occur at the upper limits of the thorax. (2)Inferior thoracic aperture or thoracic inlet. occur at the lower limits of the thorax

Answer 127

.Definition:The chest cavity communicates with the root of the neck through a narrow opening called the superior aperture or thoracic outlet. .Location:(1)The opening at the superior end of the rib cage through which cervical structures enter the thorax. (2)It marks the boundary between the neck & the superior mediastinum .Reason of nomenclature:This is called thoracic outlet,especially clinically,because important vessels and nerves emerge from the thorax here to enter the neck and upper limbs. .Direction:The outlet is obliquely directed +Facing upward and forward, and +Conveys the esophagus, trachea, and several vessels and nerves. +Because of the angled tilt of the opening, the apices of the lungs and pleurae project upward Into the neck. .Boundaries:(I)Posteriorly:The body of the 1st thoracic vertebra(T1). (II)Laterally(on both sides):The medial edges of the first ribs and their costal cartilages. (III)Anteriorly:The superior margin of the manubrium sterni .Contents:Structures that pass through the thoracic inlet(The thoracic outlet transmits structures that pass between the thorax: and the neck (esophagus, trachea, blood vessels, etc.) and for the most part lie close to the midline): (I)Tubes:(1)Trachea (2)Oesophagus (II)Nerves:(1)Phrenic nerve (2)Vagus nerve (3)Recurrent laryngeal nerve (4)Sympathetic trunks (III)Arteries:(1)Common carotid arteries (2)Brachiocephalic trunk (3)Subclavian arteries +Scalenus anterior has 2 parts,the subclavian artery leaves the thorax by passing over the 1st rib and between these 2 portions of the muscle. +The subclavian artery lies posterior to scalenus anterior,the vein lies in front. +The subclavian artery passes anterior to the middle scalene. (IV)Veins:(1)Internal jugular veins (2)Brachiocephalic veins (3)Subclavian veins +The subclavian vein is the most anterior structure and is immediately anterior to scalenus anterior and its attachment to the 1st rib. (V)Lymphatic vessels and lymph nodes .SURGICAL IMPORTANCE: Thoracic outlet syndrome

Answer 128

(1) Thoracic outlet. (2) Root of the neck

Answer 129

The chest cavity communicates with the root of the neck through a narrow opening called the superior aperture or thoracic outlet.

Answer 130

(1)The opening at the superior end of the rib cage through which cervical structures enter the thorax. (2)It marks the boundary between the neck & the superior mediastinum.

Answer 131

This is called thoracic outlet,especially clinically,because important vessels and nerves emerge from the thorax here to enter the neck and upper limbs.

Answer 132

The outlet is obliquely directed +Facing upward and forward, and +Conveys the esophagus, trachea, and several vessels and nerves. +Because of the angled tilt of the opening, the apices of the lungs and pleurae project upward into the neck.

Answer 133

(I)Posteriorly:The body of the 1st thoracic vertebra(T1). (II)Laterally(on both sides):The medial edges of the first ribs and their costal cartilages. (III)Anteriorly:The superior margin of the manubrium sterni

Answer 134

Structures that pass through the thoracic inlet(The thoracic outlet transmits structures that pass between the thorax and the neck(esophagus, trachea, blood vessels, etc.) and for the most part lie close to the midline): (I)Tubes:(1)Trachea (2)Oesophagus (II)Nerves:(1)Phrenic nerve (2)Vagus nerve (3)Recurrent laryngeal nerve (4)Sympathetic trunks (III)Arteries:(1)Common carotid arteries (2)Brachiocephalic trunk (3)Subclavian arteries +Scalenus anterior has 2 parts,the subclavian artery leaves the thorax by passing over the 1st rib and between these 2 portions of the muscle. +The subclavian artery lies posterior to scalenus anterior,the vein lies in front. +The subclavian artery passes anterior to the middle scalene. (IV)Veins:(1)Internal jugular veins (2)Brachiocephalic veins (3)Subclavian veins +The subclavian vein is the most anterior structure and is immediately anterior to scalenus anterior and its attachment to the 1st rib. (V)Lymphatic vessels and lymph nodes

Answer 135

Thoracic outlet syndrome

Answer 136

.Definition:Obstruction of the thoracic outlet compressing the neurovascular structures on the upper surface of the 1st rib. .C/P:(I)Brachial plexus of nerves(C5 to 8 and T1) related symptoms 1)The brachial plexus of nerves (C5 to 8 and Tl) and the subclavian artery and vein are closely related to the upper surface of the first rib and the clavicle as they enter the upper limb. 2)Most of the symptoms are caused by pressure on the lower trunk of the plexus,causing: +Pain down the medial side of the forearm and hand. +Wasting of small muscles of the hand. (II)Blood vessels(subclavian vessels)related symptoms Pressure on the blood vessels may compromise the circulation of the upper limb.

Answer 137

Obstruction of the thoracic outlet compressing the neurovascular structures on the upper surface of the 1st rib.

Answer 138

(I)Brachial plexus of nerves(C5 to 8 and T1) related symptoms 1)The brachial plexus of nerves (C5 to 8 and Tl) and the subclavian artery and vein are closely related to the upper surface of the first rib and the clavicle as they enter the upper limb. 2)Most of the symptoms are caused by pressure on the lower trunk of the plexus,causing: +Pain down the medial side of the forearm and hand. +Wasting of small muscles of the hand. (II)Blood vessels(subclavian vessels)related symptoms Pressure on the blood vessels may compromise the circulation of the upper limb.

Answer 139

.Definition:The thoracic cavity communicates with the abdomen through a large opening called the inferior thoracic aperture. Boundaries:(1)Posteriorly:The body of the 12th thoracic vertebra (2)Laterally:The curving costal margin (3)Anteriorly:The xiphisternal joint (4)Inferiorly:The diaphragm-closes the inferior aperture. .Contents:Structures that pass between the thoracic and abdominal cavities (e.g., esophagus, aorta) must either pierce the diaphragm or go around the diaphragm.

Answer 140

.Definition:A dense fascial layer closes the thoracic outlet on either side. .Shape:Tent shaped .Features:(1)Dense (2)Fibrous sheet (3)Thickening of endothoracic fascia .Function:(1)It protects the underlying cervical pleura and (2)Resists the changes in intrathoracic pressure occurring during respiratory movements. .Attachment:I)Laterally:to the medial border of the 1st rib and costal cartilage II)Medially:to the fascia Investing the structures passing from the thorax into the neck.

Answer 141

A dense fascial layer closes the thoracic outlet on either side. .

Answer 142

Shape:Tent shaped .Features:(1)Dense (2)Fibrous sheet (3)Thickening of endothoracic fascia .Function:(1)It protects the underlying cervical pleura and (2)Resists the changes in intrathoracic pressure occurring during respiratory movements. .Attachment:I)Laterally:to the medial border of the 1st rib and costal cartilage II)Medially:to the fascia Investing the structures passing from the thorax into the neck.

Answer 143

Features:(1)Dense (2)Fibrous sheet (3)Thickening of endothoracic fascia .Function:(1)It protects the underlying cervical pleura and (2)Resists the changes in intrathoracic pressure occurring during respiratory movements. .Attachment:I)Laterally:to the medial border of the 1st rib and costal cartilage II)Medially:to the fascia Investing the structures passing from the thorax into the neck.

Answer 144

(1)It protects the underlying cervical pleura and (2)Resists the changes in intrathoracic pressure occurring during respiratory movements.

Answer 145

I)Laterally:to the medial border of the 1st rib and costal cartilage II)Medially:to the fascia Investing the structures passing from the thorax into the neck.

Answer 146

.Definition:a thin layer of loose connective tissue. .Function:(1)Separates the parietal pleura from the thoracic wall. (2)The innermost intercostal muscle is lined internally by the endothoracic fascia, which is lined internally by a highly variable extrapleural fatty layer and then the parietal pleura.

Answer 147

A thin layer of loose connective tissue.

Answer 148

(1)Separates the parietal pleura from the thoracic wall. (2)The innermost intercostal muscle is lined internally by the endothoracic fascia, which is lined internally by a highly variable extrapleural fatty layer and then the parietal pleura.

Answer 149

.Definition:Are the gaps between adjacent ribs. .Layers of thoracic wall: A needle passing through the entire depth of an intercostal space must penetrate seven structural layers.These are most pronounced in the lateral aspect of the thoracic wall. In superficial to deep sequence, the layers are the following: 1. Skin 2. Superficial fascia 3. Deep fascia 4. Intercostal muscles +Depending on the specific location on the thoracic wall, an additional layer of muscle, the **serratus anterior**, may cover the intercostal muscle layer. +Three intercostal muscles fill the intercostal spaces +The three intercostal muscles all act as muscles of respiration. +From superficial to deep, these are:1)the external intercostal 2)the internal intercostal, and 3)the innermost intercostal muscles. +The intercostal nerves and blood vessels(the neurovascular bundle), as in abdominal wall, run between the intermediate(middle)and deepest deepest(innermost)layers of muscles.They are arranged in the following order from above downward: intercostal vein, intercostal artery, and intercostal nerve (i.e., VAN). 5. Endothoracic fascia +The innermost intercostal muscle is lined internally by the endothoracic fascia, which is lined internally by a highly variable extrapleural fatty layer and then the parietal pleura. 6. Extrapleural fatty layer 7. Parietal pleura

Answer 150

Are the gaps between adjacent ribs.

Answer 151

.Layers of thoracic wall: A needle passing through the entire depth of an intercostal space must penetrate seven structural layers.These are most pronounced in the lateral aspect of the thoracic wall. In superficial to deep sequence, the layers are the following: 1. Skin 2. Superficial fascia 3. Deep fascia 4. Intercostal muscles +Depending on the specific location on the thoracic wall, an additional layer of muscle, the serratus anterior, may cover the intercostal muscle layer. +Three intercostal muscles fill the intercostal spaces +The three intercostal muscles all act as muscles of respiration. +From superficial to deep, these are:1)the external intercostal 2)the internal intercostal, and 3)the innermost intercostal muscles. +The intercostal nerves and blood vessels(the neurovascular bundle), as in abdominal wall, run between the intermediate(middle)and deepest deepest(innermost)layers of muscles.They are arranged in the following order from above downward: intercostal vein, intercostal artery, and intercostal nerve (i.e., VAN). 5. Endothoracic fascia .Definition:A thin layer of loose connective tissue. .Function:(1)Separates the parietal pleura from the thoracic wall. (2)The innermost intercostal muscle is lined internally by the endothoracic fascia, which is lined internally by a highly variable extrapleural fatty layer and then the parietal pleura. 6. Extrapleural fatty layer 7. Parietal pleura.

Answer 152

.Features:Is the most superficial of the three intercostal muscle layers .Direction of fibres:(1)Its fibres are directed downward and forward (2)The muscle extends forward to the costal cartilage where it is replaced by an aponeurosis,the anterior(external) intercostal membrane. .Attachment:I)Origin:Inferior border of the rib above II)Insertion:Superior border of the rib below .Nerve supply:Intercostal nerves. .Action:(1)Stabilise the rib cage. (2)With 1st rib fixed,they raise ribs during inspiration thus increase anterio posterior and transverse diameters of thorax.

Answer 153

Is the most superficial of the three intercostal muscle layers

Answer 154

(1)Its fibres are directed downward and forward (2)The muscle extends forward to the costal cartilage where it is replaced by an aponeurosis,the anterior(external)intercostal membrane.

Answer 155

I)Origin:Inferior border of the rib above II)Insertion:Superior border of the rib below

Answer 156

Intercostal nerves.

Answer 157

(1)Stabilise the rib cage. (2)With 1st rib fixed,they raise ribs during inspiration thus increase anterioposterior and transverse diameters of thorax.

Answer 158

.Features:Forms the intermediate intercostal layer. .Direction of fibres:(1)Its fibres are directed downward and backward. (2)The muscle extends backward from the sternum in front to the angles of the ribs behind,where the muscle is replaced by an aponeurosis,the posterior(internal)intercostal membrane. .Attachment:(I)Origin:Subcostal groove at the inferior border of the rib above. (II)Insertion:Superior or upper border of the rib below. .Nerve supply:Intercostal nerves. .Action:Stabilise the rib cage: With last rib fixed by abdominal muscles, they lower ribs during expiration.

Answer 159

Forms the intermediate intercostal layer

Answer 160

(1)Its fibres are directed downward and backward. (2)The muscle extends backward from the sternum in front to the angles of the ribs behind,where the muscle is replaced by an aponeurosis,the posterior (internal)intercostal membrane.

Answer 161

(I)Origin:Subcostal groove at the inferior border of the rib above. (II)Insertion:Superior or upper border of the rib below.

Answer 162

Intercostal nerves.

Answer 163

Stabilise the rib cage: With last rib fixed by abdominal muscles, they lower ribs during expiration.

Answer 164

.Features:(I)Forms the deepest intercostal layer (II)Corresponds to the transversus abdominis muscle in the anterior abdominal wall. (III)It is an incomplete muscle layer and crosses more than one intercostal space. .Relations:I)Internally to the-endothoracic fascia and parietal pleura II)Externally to the-intercostal nerves and vessels. .Devisions:The innermost intercostal muscle can be divided into three portions, which are more or less separate from one another: I)The anterior portion is named the transversus thoracis muscle. II)The lateral portion is the innermost intercostal muscle. III)The posterior portion is the subcostalis muscle. .Attachment:I)Origin:Adjacent ribs III)Insertion:Adjacent ribs .Nerve supply:Intercostal nerves .Action:Assists external and internal intercostal muscles

Answer 165

(1)The primary function of the intercostal muscles during respiration appears to be to stabilise the position of the ribs to maintain the intercostal spaces. (2)Their actions in elevation (external intercostals) and depression (inter- nal intercostals) of the ribs are most likely to occur during forced respiration. (3)In addition, the tone of the intercostal muscles during the different phases of respiration serves to strengthen the tissues of the intercostal spaces, thus preventing the sucking in or the blowing out of the tissues with changes in intrathoracic pressure.

Answer 166

(1) Thin (2) Muscular (3) Tendinous septum

Answer 167

I)As seen from in front-It is dome shaped +The diaphragm curves into Rt and Lt domes(cupulae). +The arching domes of the diaphragm can reach the level of the fifth rib (the right dome can reach a higher level). +Th Rt dome:(1)The arching dome reaches as high as the upper border of the 5th rib. (2)Lies at a higher level because of the large size of the Rt lobe of the liver. +The Lt dome:The arching may reach the lower border of the 5th rib. +The domes support the Rt and Lt lungs II)When seen from the side-The diaphragm has the appearance of an inverted J with the:- (1)Long limb-Extending up from the vertebral column (2)Short limb-Extending forward to the xiphoid process

Answer 168

It consists of :- 1st/Origin:Peripheral muscular part -Which arises from the margins of the thorax. -The origin of the diaphragm can be divided into 3 parts: (I)Sternal part:arising from the posterior surface of the xiphoid process. (II)Costal part:arising from the deep surfaces of the lower six ribs and their costal cartilages. (III)Vertebral part:(a)2 crura-arising by vertebral column 1)The Rt crus:arises from the sides and front of the bodies of the first or upper 3 lumbar vertebrae and the intervertebral discs. 2)The Lt crus:arises from the sides and front of the bodies of the first or upper 2 lumbar vertebrae and the intervertebral discs. (b)5 arcuate ligaments-arising from the arcuate ligaments lateral to the crura(i.e.,lateral to the crura the diaphragm arises from the:) 1)The medial arcuate ligament(2 ligaments) +extends from the sides of the body the 2nd lumbar vertebra to the tip of the transverse process of the 1st lumbar vertebra. +bridges over psoas major muscle. 2)The lateral arcuate ligaments(2 ligaments) +extends from the tip of the transverse process of the 1st lumbar vertebra to the lower border of the 12th rib. +bridges over quadratus lumborum 3)The median arcuate ligament(1 ligament) +which crosses over the anterior surface of the aorta +connects the medial borders of the two crura 2nd/Insertion:a central tendon -Definition:A centrally placed tendon -Location:The central tendon lies at the level of the xiphosternal joint -Shape:Is shaped like three leaves -Function:I)Insertion point:The diaphragm inserts into a central tendon II)Heart support:(1)The central tendon supports the heart (2)The superior surface of the tendon is partially fused with the inferior surface of the fibrous pericardium. III)Oesophageal sphincter:(1)Some of the muscle fibres of the Rt crus pass up to the Lt and surround the oesophageal orifice in a sling like loop. (2)These fibres appear to act as a sphincter and possibly assist in the prevention of regurgitation of the stomach contents into the thoracic part of the oesophagus.

Answer 169

It is dome shaped. +The diaphragm curves into Rt and Lt domes(cupulae). +The arching domes of the diaphragm can reach the level of the fifth rib (the right dome can reach a higher level). +The Rt dome:(1)The arching dome reaches as high as the upper border of the 5th rib. (2)Lies at a higher level because of the large size of the Rt lobe of the liver. +The Lt dome:The arching dome may reach the lower border of the 5th rib. +The domes support the Rt and Lt lungs

Answer 170

The diaphragm has the appearance of an inverted J with the:- (1) The long limb:Extending UP from the vertebral column. (2) The short limb:Extending FORWARD to the xiphoid process

Answer 171

Origin:Peripheral muscular part -Which arises from the margins of the thorax -The origin of the diaphragm can be divided into 3 parts I)Sternal part:arising from the posterior surface of the xiphoid process. II)Costal part:arising from the deep surfaces of the lower six ribs and their costal cartilages. III)Vertebral part:(a)2 crura-arising by vertebral column 1)The Rt crus:arises from the sides and front of the bodies of the first or upper 3 lumbar vertebrae and the intervertebral discs. 2)The Lt crus:arises from the sides and front of the bodies of the first or upper 2 lumbar vertebrae and the intervertebral discs. (b)5 arcuate ligaments-arising from the arcuate ligaments lateral to the crura(i.e.,lateral to the crura the diaphragm arises from the:) 1)The medial arcuate ligament(2 ligaments) +extends from the sides of the body the 2nd lumbar vertebra to the tip of the transverse process of the 1st lumbar vertebra. +bridges over psoas major muscle. 2)The lateral arcuate ligaments(2 ligaments) +extends from the tip of the transverse process of the 1st lumbar vertebra to the lower border of the 12th rib. +bridges over quadratus lumborum 3)The median arcuate ligament(1 ligament) +which crosses over the anterior surface of the aorta +connects the medial borders of the two crura

Answer 172

Arising from the posterior surface of the xiphoid process

Answer 173

Arising from the deep surfaces of the lower six ribs and their costal cartilages

Answer 174

a)2 crura-arising by vertebral column 1)The Rt crus:arises from the sides and front of the bodies of the first or upper 3 lumbar vertebrae and the intervertebral discs. 2)The Lt crus:arises from the sides and front of the bodies of the first or upper 2 lumbar vertebrae and the intervertebral discs. (b)5 arcuate ligaments-arising from the arcuate ligaments lateral to the crura(i.e.,lateral to the crura the diaphragm arises from the:) 1)The medial arcuate ligament(2 ligaments) +extends from the sides of the body the 2nd lumbar vertebra to the tip of the transverse process of the 1st lumbar vertebra. +bridges over psoas major muscle. 2)The lateral arcuate ligaments(2 ligaments) +extends from the tip of the transverse process of the 1st lumbar vertebra to the lower border of the 12th rib. +bridges over quadratus lumborum 3)The median arcuate ligament(1 ligament) +which crosses over the anterior surface of the aorta +connects the medial borders of the two crura

Answer 175

2 crura-arising by vertebral column 1)The Rt crus:arises from the sides and front of the bodies of the first or upper 3 lumbar vertebrae and the intervertebral discs. 2)The Lt crus:arises from the sides and front of the bodies of the first or upper 2 lumbar vertebrae and the intervertebral discs.

Answer 176

arising by vertebral column

Answer 177

arises from the sides and front of the bodies of the first or upper 3 lumbar vertebrae and the intervertebral discs.

Answer 178

arises from the sides and front of the bodies of the first or upper 2 lumbar vertebrae and the intervertebral discs.

Answer 179

5 arcuate ligaments-arising from the arcuate ligaments lateral to the crura (i.e.,lateral to the crura the diaphragm arises from the:) 1)The medial arcuate ligament(2 ligaments) +extends from the sides of the body the 2nd lumbar vertebra to the tip of the transverse process of the 1st lumbar vertebra. +bridges over psoas major muscle. 2)The lateral arcuate ligaments(2 ligaments) +extends from the tip of the transverse process of the 1st lumbar vertebra to the lower border of the 12th rib. +bridges over quadratus lumborum 3)The median arcuate ligament(1 ligament) +which crosses over the anterior surface of the aorta +connects the medial borders of the two crura

Answer 180

5 arcuate ligaments-arising from the arcuate ligaments lateral to the crura

Answer 181

(2 ligaments) +Extends from the side of the body of the 2nd lumbar vertebra to the tip of the transverse process of the 1st lumbar vertebra +Bridges over the psoas major

Answer 182

(2 ligaments) +extends from the tip of the transverse process of the 1st lumbar vertebra to the lower border of the 12th rib. +bridges over quadratus lumborum

Answer 183

(1 ligament) +which crosses over the anterior surface of the aorta +connects the medial borders of the two crura

Answer 184

Insertion:a central tendon -Definition:A centrally placed tendon -Location:The central tendon lies at the level of the xiphosternal joint -Shape:Is shaped like three leaves -Function:I)Insertion point:The diaphragm inserts into a central tendon II)Heart support:(1)The central tendon supports the heart (2)The superior surface of the tendon is partially fused with the inferior surface of the fibrous pericardium. III)Oesophageal sphincter:(1)Some of the muscle fibres of the Rt crus posterior ass up to the Lt and surround the oesophageal orifice in a sling like loop. (2)These fibres appear to act as a sphincter and possibly assist in the prevention of regurgitation of the stomach contents into the thoracic part of the oesophagus.

Answer 185

A centrally placed tendon

Answer 186

Is shaped like three leaves

Answer 187

I)Insertion point:The diaphragm inserts into a central tendon II)Heart support:(1)The central tendon supports the heart (2)The superior surface of the tendon is partially fused with the inferior surface of the fibrous pericardium. III)Oesophageal sphincter:(1)Some of the muscle fibres of the Rt crus pass up to (2)These fibres appear to act as a sphincter and possibly assist in the prevention of regurgitation of the stomach contents into the thoracic part of the oesophagus.

Answer 188

The diaphragm inserts into a central tendon

Answer 189

(1)The central tendon supports the heart (2)The superior surface of the tendon is partially fused with the inferior surface of the fibrous pericardium.

Answer 190

(1)Some of the muscle fibres of the Rt crus pass up to posterior ass up to the Lt and surround the oesophageal orifice in a sling like loop. (2)These fibres appear to act as a sphincter and possibly assist in the prevention of regurgitation of the stomach contents into the thoracic part of the oesophagus.

Answer 191

1st/The phrenic nerve I)Motor nerve supply:(1)Comes from the Rt and Lt phrenic nerve(C3,4,5). (2)Each phrenic nerve supplies approximately half of the diaphragm.Thus,functionally,the diaphragm operates as two hemidiaphragms. II)Sensory nerve supply:The phrenic nerves supply the:(1)Parietal pleura (2)Peritoneum covering the central surfaces of the diaphragm. 2nd/The lower six intercostal nerves Supply the periphery of the diaphragm.

Answer 192

.Location:They lie at the base of the neck being (1)Anterior to the scalenus anterior muscles (2)Beneath the pre-vertebral fascia .Origin:I)The phrenic nerve arises from the neck II)They are branches of the cervical plexus III)From the anterior rami of the 3rd,4th and 5th cervical nerves(C3,4,5) IV)Comes from the Rt and Lt phrenic nerve .Course:I)*_Both nerves_* (1)They run vertically downward across the front of the scalenus anterior muscle. (2)They enter the thorax by passing superficial to (or in front of ) the subclavian artery. (3)Run anterior the root of the lung (4)The distribution of the phrenic nerve on the diaphragm is best seen on the inferior surface (5)Each phrenic nerve supplies approximately half of the diaphragm.Thus functionally,the diaphragm operates as two hemidiaphragm. II)*_The Rt phrenic nerve_* (1)Descends in the thorax along the Rt side of the +Rt Brachiocephalic vein +Superior vena cava(SVC) (2)It passes in front of the root of the Rt lung (3)Runs along the Rt side of the pericardium,which separates the nerve from the Rt atrium (4)It then descends on the Rt side of the inferior vena cava(IVC) to the diaphragm (5)Its terminal branches pass through the caval opening in the diaphragm to supply the central part of the peritoneum on its abdominal aspect III)*_The Lt phrenic nerve_* (1)Descends in the thorax along the Lt side of the subclavian artery (2)It crosses the Lt side of the aortic arch and here crosses over the Lt vagus nerve (3)It passes in front of the root of the lung and then descends over the Lt surface of the pericardium,which separates the nerve from the Lt ventricle (4)On reaching the diaphragm, the terminal branches pierce the muscle and supply the central part of the peritoneum on its abdominal aspect Types of fibres:The phrenic nerves possess both efferent and afferent fibers. I)The efferent flbes:are the sole motor supply to the muscle of the diaphragm. II)The afferent fibers:carry sensation to the central nervous system from the:- (1)peritoneum covering the central region of the undersurface of the diaphragm. (2)pleura covering the central region of the upper surface of the diaphragm. (3)pericardium (4)mediastinal parietal pleura. .Clinical importance:Causes of Diaphragm paralysis (1) Pressure from malignant tumours in the mediastinum (2)Surgical crushing or sectioning of the phrenic nerve +producing paralysis the diaphragm on one side +was once used as part of the treatment of lung tuberculosis,especially of the lower lobes. +In such cases,the immobile dome of the elevated diaphragm rests the lung.

Answer 193

I)Muscle of separation:Separates the chest cavity above from the abdominal cavity below. II)A passage route:Structures that pass between the thoracic and abdominal cavity (e.g.,oesophagus,aorta)must either pierce the diaphragm or go around the diaphragm. III)Muscle of inspiration:(1)The diaphragm is the most important muscle of respiration. (2)The diaphragm is the most important muscle of inspiration. (3)On contraction, the diaphragm pulls its central tendon down and increases the vertical diameter of the thorax. (4)Recognising that the diaphragm flattens during contraction (inspiration) and elevates during relaxation (expiration) is important IV)Muscle of abdominal straining:(1)The contraction of the diaphragm assists the contraction of the muscles of the anterolateral abdominal wall in raising the intra-abdominal pressure for micturition, defecation, and parturition. (2)Taking a deep breath and closing the glottis of the larynx further aids this mechanism. The diaphragm is unable to rise because of the air trapped in the respiratory tract. Now and again, air is allowed to escape, producing a grunting sound. V)Weight-lifting muscle: In a person taking a deep breath and holding it (fixing the diaphragm), the diaphragm assists the muscles of the anterolateral abdominal wall in raising the intra- abdominal pressure to such an extent that it helps support the vertebral column and prevent flexion. This greatly assists the postvertebral muscles in the lifting of heavy weights. Needless to say, adequate sphincteric control of the bladder and anal canal is important under these circumstances VI)Thoracoabdominal pump:(1)The descent of the diaphragm decreases the intrathoracic pressure and at the same time increases the intra-abdominal pressure. (2)This pressure change compresses the blood in the inferior vena cava and forces it upward into the right atrium of the heart. Lymph within the abdominal lymph vessels is also compressed, and the negative intrathoracic pressure aids its passage upward within the thoracic duct. (3)The presence of valves within the thoracic duct prevents backflow.

Answer 194

Separates the chest cavity above from the abdominal cavity below.

Answer 195

Structures that pass between the thoracic and abdominal cavity (e.g.,oesophagus,aorta)must either pierce the diaphragm or go around the diaphragm.

Answer 196

(1)The diaphragm is the most important muscle of respiration. (2)The diaphragm is the most important muscle of inspiration. (3)On contraction, the diaphragm pulls its central tendon down and increases the vertical diameter of the thorax. (4)Recognising that the diaphragm flattens during contraction (inspiration) and elevates during relaxation (expiration) is important

Answer 197

(1)The contraction of the diaphragm assists the contraction of the muscles of the anterolateral abdominal wall in raising the intra-abdominal pressure for micturition,defecation, and parturition. (2)Taking a deep breath and closing the glottis of the larynx further aids this mechanism. (3)The diaphragm is unable to rise because of the air trapped in the respiratory tract.Now and again, air is allowed to escape,producing a grunting sound.

Answer 198

In a person taking a deep breath and holding it (fixing the diaphragm), the diaphragm assists the muscles of the anterolateral abdominal wall in raising the intra- abdominal pressure to such an extent that it helps support the vertebral column and prevent flexion. This greatly assists the postvertebral muscles in the lifting of heavy weights. Needless to say, adequate sphincteric control of the bladder and anal canal is important under these circumstances

Answer 199

(1)The descent of the diaphragm decreases the intrathoracic pressure and at the same time increases the intra-abdominal pressure. (2)This pressure change compresses the blood in the inferior vena cava and forces it upward into the right atrium of the heart. Lymph within the abdominal lymph vessels is also compressed, and the negative intrathoracic pressure aids its passage upward within the thoracic duct. (3)The presence of valves within the thoracic duct prevents backflow.

Answer 200

They lie at the base of the neck being (1) Anterior to the scalenus anterior muscles (2) Beneath the pre-vertebral fascia Gg

Answer 201

I)The phrenic nerve arises from the neck II)They are branches of the cervical plexus III)From the anterior rami of the 3rd,4th and 5th cervical nerves(C3,4,5) IV)Comes from the Rt and Lt phrenic nerve

Answer 202

I)Both nerves (1)They run vertically downward across the front of the scalenus anterior muscle. (2)They enter the thorax by passing superficial to (or in front of ) the subclavian artery. (3)Run anterior the root of the lung (4)The distribution of the phrenic nerve on the diaphragm is best seen on the inferior surface (5)Each phrenic nerve supplies approximately half of the diaphragm.Thus functionally,the diaphragm operates as two hemidiaphragm. II)The Rt phrenic nerve (1)Descends in the thorax along the Rt side of the +Rt Brachiocephalic vein +Superior vena cava(SVC) (2)It passes in front of the root of the Rt lung (3)Runs along the Rt side of the pericardium,which separates the nerve from the Rt atrium (4)It then descends on the Rt side of the inferior vena cava(IVC) to the diaphragm (5)Its terminal branches pass through the caval opening in the diaphragm to supply the central part of the peritoneum on its abdominal aspect III)The Lt phrenic nerve (1)Descends in the thorax along the Lt side of the subclavian artery (2)It crosses the Lt side of the aortic arch and here crosses over the Lt vagus nerve (3)It passes in front of the root of the lung and then descends over the Lt surface of the pericardium,which separates the nerve from the Lt ventricle (4)On reaching the diaphragm, the terminal branches pierce the muscle and supply the central part of the peritoneum on its abdominal aspect

Answer 203

(1)They run vertically downward across the front of the scalenus anterior muscle. (2)They enter the thorax by passing superficial to (or in front of ) the subclavian artery. (3)Run anterior the root of the lung (4)The distribution of the phrenic nerve on the diaphragm is best seen on the inferior surface (5)Each phrenic nerve supplies approximately half of the diaphragm.Thus functionally,the diaphragm operates as two hemidiaphragm.

Answer 204

(1)Descends in the thorax along the Rt side of the +Rt Brachiocephalic vein +Superior vena cava(SVC) (2)It passes in front of the root of the Rt lung (3)Runs along the Rt side of the pericardium,which separates the nerve from the Rt atrium (4)It then descends on the Rt side of the inferior vena cava(IVC) to the diaphragm (5)Its terminal branches pass through the caval opening in the diaphragm to supply the central part of the peritoneum on its abdominal aspect

Answer 205

(1)Descends in the thorax along the Lt side of the subclavian artery (2)It crosses the Lt side of the aortic arch and here crosses over the Lt vagus nerve (3)It passes in front of the root of the lung and then descends over the Lt surface of the pericardium,which separates the nerve from the Lt ventricle (4)On reaching the diaphragm, the terminal branches pierce the muscle and supply the central part of the peritoneum on its abdominal aspect

Answer 206

are the sole motor supply to the muscle of the diaphragm

Answer 207

carry sensation to the central nervous system from the:- (1)peritoneum covering the central region of the undersurface of the diaphragm. (2)pleura covering the central region of the upper surface of the diaphragm. (3)pericardium (4)mediastinal parietal pleura.

Answer 208

Aetiology: (1) Pressure from malignant tumours in the mediastinum (2)A single dome of the diaphragm(i.e.,a hemidiaphragm)may be paralysed by surgical crushing or sectioning of the phrenic nerve in the neck +producing paralysis the diaphragm on one side +was once used as part of the treatment of lung tuberculosis,especially of the lower lobes. +In such cases,the immobile dome of the elevated diaphragm rests the lung. The accessory nerve exploitation: (1)This may be necessary in the treatment of certain forms of lung tuberculosis,when the physician wishes to rest the lower lobe of the lung on one side. (2)Occasionally, the contribution from the 5th cervical spinal nerve joins the phrenic nerve late as a branch from the nerve to the subclavius.This is known as the accessory phrenic nerve. (3)To obtain complete paralysis under these circumstances,the nerve to the subclavius muscle must also be sectioned. (4)Recognising that a paralysed hemidiaphragm assumes a hyperelevated posture rather than a depressed(flattened) posture is important.

Answer 209

(1) Pressure from malignant tumours in the mediastinum (2)A single dome of the diaphragm(i.e.,a hemidiaphragm)may be paralysed by surgical crushing or sectioning of the phrenic nerve in the neck +producing paralysis of the diaphragm on one side +was once used as part of the treatment of lung tuberculosis,especially of the lower lobes. +In such cases,the immobile dome of the elevated diaphragm rests the lung.

Answer 210

(1)Paralysis of the diaphragm may be necessary in the treatment of certain forms of lung tuberculosis,when the physician wishes to rest the lower lobe of the lung on one side. (2)Occasionally, the contribution from the 5th cervical spinal nerve joins the phrenic nerve late as a branch from the nerve to the subclavius.This is known as the accessory phrenic nerve. (3)To obtain complete paralysis under these circumstances,the nerve to the subclavius muscle must also be sectioned. (4)Recognising that a paralysed hemidiaphragm assumes a hyperelevated posture rather than a depressed(flattened) posture is important.

Answer 211

Aetiology: Penetrating injuries to the diaphragm can result from stab or bullet wounds to the chest or abdomen. Feature: Any penetrating wound to the chest below the level of the nipples should be suspected of causing damage to the diaphragm until proved otherwise. The arching domes of the diaphragm can reach the level of the fifth rib (the right dome can reach a higher level).

Answer 212

Penetrating injuries to the diaphragm can result from stab or bullet wounds to the chest or abdomen.

Answer 213

Any penetrating wound to the chest below the level of the nipples should be suspected of causing damage to the diaphragm until proved otherwise. The arching domes of the diaphragm can reach the level of the fifth rib (the right dome can reach a higher level).

Answer 214

Definition: Hiccup is the involuntary spasmodic contraction of the diaphragm accompanied by the (1)approximation of the vocal folds and (2)closure of the glottis of the larynx Incidence: It is a common condition in normal individuals Aetiology: (1)Occurs after eating or drinking as a result of gastric irritation of the vagus nerve endings. (2)However, it may be a symptom of disease such as: a)pleurisy b)peritonitis c)pericarditis d)uremia.

Answer 215

^{Hiccup is the involuntary spasmodic contraction of the diaphragm
accompanied by the
(1)approximation of the vocal folds and
(2)closure of the glottis of the larynx}

Answer 216

It is a common condition in normal individuals

Answer 217

(1)Occurs after eating or drinking as a result of gastric irritation of the vagus nerve endings. (2)However, it may be a symptom of disease such as: a)pleurisy b)peritonitis c)pericarditis d)uremia.

Answer 218

Overview The diaphragm, pericardium & heart are formed in the neck, and thus obtain their nerve supply from there. They migrate to their final sites carrying their nerve supply with them. Timing Between the 5th and 7th weeks of gestation The diaphragm is formed from or through the progressive fusion of the following:- 1st/The septum transversum .Definition:is a mass of mesoderm .Formation:Formed in the neck by fusion of the myotomes of the 3rd,4th and 5th cervical segments .Nerve supply development:(1)With the descent of the heart from the neck to the thorax, the septum is pushed caudally pulling its nerve supply with it. (2)The muscular origins of the diaphragm are somites located in cervical segments 3 to 5, which accounts for the long path taken by the phrenic nerve.Thus,cervical nerves C3 to 5 form the phrenic nerve, which supplies the diaphragm. (3)The motor nerve supply to the entire muscle of the diaphragm is the phrenic nerve. (4)The sensory innervation of the peripheral parts of the pleura and peritoneum covering the peripheral areas of the upper and lower surfaces of the diaphragm is from the lower six thoracic nerves (5)This is understandable, because the peripheral pleura and peritoneum from the pleuroperitoneal membranes are derived from the body wall. .Function:(1)It descends from the neck to form the muscle and central tendon During the process of fusion of the pleuroperitoneal membranes with the: a)Septum transversum anterior to the oesophagus b)Dorsal mesentry posterior to the oesophagus (2)During the process of fusion, the mesoderm of the septum transversum extends into the other parts, forming all the musculature of the diaphragm. (3)The septum transversum separates the pericardial development (ventrally)from developing gut(dorsally). It moves to lie caudal to peritoneal cavity. 2nd/The body wall(transverse layer)and the two pleuroperitoneal membranes: .Function:(1)The pleuroperitoneal membranes grow medially from the body wall on each side until they fuse with the: a)septum transversum anterior to the esophagus b)dorsal mesentery posterior to the esophagus (2) are largely responsible for the peripheral areas of the diaphragmatic pleura and peritoneum,or in another words parietal membranes surrounding viscera,that cover its upper and lower surfaces, respectively. (3)Both the body wall and the two pleuroperitoneal membranes grow inward to fuse with the septum transversum and give the diaphragm. 3rd/The dorsal mesentry of oesophagus: .Function:in which the crura develop .Location:completes the diaphragm posteriorly 4th/Cervical somites C3 to C5 .Form the muscular component of the diaphragm

Answer 219

* *Relations of the Upper Surface:-** (1) PIeura & lung on both sides. (2) Base of pericardium in the middle. * *Relations of the lower surface:-** (1) Liver, kidney & suprarenal gland (on both sides). (2) Spleen & stomach (on the left).

Answer 220

(1) Congenital diaphragmatic hernia (2) Acquired diaphragmatic hernia

Answer 221

Congenital diaphragmatic hernia occurs as the result of incomplete fusion of the:- (1) Septum transversum. (2) Dorsal mesentry. (3) Pleuroperitoneal membranes from the body wall

Answer 222

(1) Foramen of Morgagni or Magendi hernia (2) Bochdalek hernia

Answer 223

.Definition The opening between the xiphoid and costal origins of the diaphragm .Location Usually located anteriorly and on the right through which parasternal(anterior) diaphragmatic hernia may develop .Incidence Rare type of diaphragmatic hernia(approximately 2% of cases) .C/P (1) Usually present later (2) Tend to be less symptomatic (3) Small defects:a)as defects are small,pulmonary hypoplasia is less common b) minimal compromise on lung development (4) More advanced cases may contain transverse colon .Dx Antenatal U/S:minimal signs .Prognosis Usually good prognosis .Treatment Direct anatomical repair

Answer 224

(1) Magendi hernia (2) Anterior diaphragmatic hernia

Answer 225

The opening between the xiphoid and costal origins of the diaphragm .

Answer 226

(1) Usually located anteriorly and (2) on the right (3) through which parasternal(anterior)diaphragmatic hernia may develop .

Answer 227

Rare type of diaphragmatic hernia(approximately 2% of cases) .

Answer 228

(1) Usually present later (2) Tend to be less symptomatic (3) Small defects:a)as defects are small,pulmonary hypoplasia is less common b) minimal compromise on lung development (4) More advanced cases may contain transverse colon .

Answer 229

Antenatal U/S:minimal signs

Answer 230

Usually good prognosis

Answer 231

Direct anatomical repair

Answer 232

.Definition Typically congenital diaphragmatic hernia due to persistent pleuroperitoneal canal caused by failure of fusion of the septum transversum with the pleuroperitoneal membranes. .Incidence (1) The most common type (2) More common in males .Location (1) Posteriorly located (2) 85% of cases are located in the left hemidiaphragm .C/P (1)Larger defect (2)Scaphoid abdomen:The classical finding is that of a scaphoid abdomen on clinical examination because of herniation of the abdominal contents into the chest. (3)Associated with:(a)Lung hypoplasia on the affected side -if Bochdalek diaphragmatic hernia is not diagnosed antenatally will typically present soon after birth with respiratory distress -infants have considerable respiratory distress due to hypoplasia of the developing lung. -Historically this was considered to be due to direct compression of the lung by herniated viscera. -This view over simplifies the situation and the pulmonary hypoplasia occurs concomitantly with the hernial development,rather than as a direct result of it. -The pulmonary hypoplasia is associated with pulmonary hypertension and abnormalities of pulmonary vasculature -The pulmonary hypertension renders infants at risk of right to left shunting(resulting in progressive and worsening of hypoxia). (b)A number of chromosomal abnormalities such as Trisomy 21 and 18. (c)Other birth defects .Dx (1) Often diagnosed antenatally (2) Chest XRs (3) Abdominal U/S (4) Cardiac echo .Treatment (1)Surgery:(a)Forms the mainstay of treatment. (b)Both thoracic and abdominal approaches may be utilised. (c)Following reduction of the hernial contents a careful search needs to be made for a hernial sac as failure to recognise and correct this will result in a high recurrence rate. (d)Placement of mesh (e)Smaller defects may be primarily closed. (f)Larger defects may require a patch to close the defect. (g)Malrotation of the viscera is a recognised association and may require surgical correction at the same procedure (favouring an abdominal approach). (2)Mechanical ventilation:In infants that have severe respiratory compromise .Prognosis (1) Poor prognosis. (2) The mortality rate:(a)is high(50-75%) (b) is related to the:1)degrees of lung compromise 2) age at presentation(considerably better in infants \>24 hours old.

Answer 233

(1) Pleuroperitoneal diaphragmatic hernia (2) Posterior diaphragmatic hernia

Answer 234

Typically congenital diaphragmatic hernia due to persistent pleuroperitoneal canal caused by failure of fusion of the septum transversum with the pleuroperitoneal membranes. .

Answer 235

(1) The most common type (2) More common in males .

Answer 236

(1) Posteriorly located (2) 85% of cases are located in the left hemidiaphragm

Answer 237

(1)Larger defect (2)Scaphoid abdomen:The classical finding is that of a scaphoid abdomen on clinical examination because of herniation of the abdominal contents into the chest. (3)Associated with:(a)Lung hypoplasia on the affected side -if Bochdalek diaphragmatic hernia is not diagnosed antenatally will typically present soon after birth with respiratory distress -infants have considerable respiratory distress due to hypoplasia of the developing lung. -Historically this was considered to be due to direct compression of the lung by herniated viscera. -This view over simplifies the situation and the pulmonary hypoplasia occurs concomitantly with the hernial development,rather than as a direct result of it. -The pulmonary hypoplasia is associated with pulmonary hypertension and abnormalities of pulmonary vasculature -The pulmonary hypertension renders infants at risk of right to left shunting(resulting in progressive and worsening of hypoxia). (b)A number of chromosomal abnormalities such as Trisomy 21 and 18. (c)Other birth defects .

Answer 238

The classical finding is that of a scaphoid abdomen on clinical examination because of herniation of the abdominal contents into the chest.

Answer 239

Associated with:(a)Lung hypoplasia on the affected side -if Bochdalek diaphragmatic hernia is not diagnosed antenatally will typically present soon after birth with respiratory distress -infants have considerable respiratory distress due to hypoplasia of the developing lung. -Historically this was considered to be due to direct compression of the lung by herniated viscera. -This view over simplifies the situation and the pulmonary hypoplasia occurs concomitantly with the hernial development,rather than as a direct result of it. -The pulmonary hypoplasia is associated with pulmonary hypertension and abnormalities of pulmonary vasculature -The pulmonary hypertension renders infants at risk of right to left shunting(resulting in progressive and worsening of hypoxia). (b)A number of chromosomal abnormalities such as Trisomy 21 and 18. (c)Other birth defects

Answer 240

Lung hypoplasia on the affected side -if Bochdalek diaphragmatic hernia is not diagnosed antenatally will typically present soon after birth with respiratory distress -infants have considerable respiratory distress due to hypoplasia of the developing lung. -Historically this was considered to be due to direct compression of the lung by herniated viscera. -This view over simplifies the situation and the pulmonary hypoplasia occurs concomitantly with the hernial development,rather than as a direct result of it. -The pulmonary hypoplasia is associated with pulmonary hypertension and abnormalities of pulmonary vasculature -The pulmonary hypertension renders infants at risk of right to left shunting(resulting in progressive and worsening of hypoxia).

Answer 241

(1) Often diagnosed antenatally (2) Chest XRs (3) Abdominal U/S (4) Cardiac echo

Answer 242

(1)Surgery:(a)Forms the mainstay of treatment. (b)Both thoracic and abdominal approaches may be utilised. (c)Following reduction of the hernial contents a careful search needs to be made for a hernial sac as failure to recognise and correct this will result in a high recurrence rate. (d)Placement of mesh (e)Smaller defects may be primarily closed. (f)Larger defects may require a patch to close the defect. (g)Malrotation of the viscera is a recognised association and may require surgical correction at the same procedure (favouring an abdominal approach). (2)Mechanical ventilation:In infants that have severe respiratory compromise .

Answer 243

(1) Poor prognosis. (2) The mortality rate:(a)is high(50-75%) (b) is related to the:1)degrees of lung compromise 2) age at presentation(considerably better in infants \>24 hours old.

Answer 244

(a) is high(50-75%) (b) is related to the:1)degrees of lung compromise 2) age at presentation(considerably better in infants \>24 hours old.

Answer 245

1) degrees of lung compromise 2) age at presentation(considerably better in infants \>24 hours old)

Answer 246

(a)Forms the mainstay of treatment. (b)Both thoracic and abdominal approaches may be utilised. (c)Following reduction of the hernial contents a careful search needs to be made for a hernial sac as failure to recognise and correct this will result in a high recurrence rate. (d)Placement of mesh (e)Smaller defects may be primarily closed. (f)Larger defects may require a patch to close the defect. (g)Malrotation of the viscera is a recognised association and may require surgical correction at the same procedure (favouring an abdominal approach).

Answer 247

Forms the mainstay of treatment.

Answer 248

Both thoracic and abdominal approaches may be utilised.

Answer 249

Following reduction of the hernial contents a careful search needs to be made for a hernial sac as failure to recognise and correct this will result in a high recurrence rate.

Answer 250

Smaller defects may be primarily closed.

Answer 251

Larger defects may require a patch to close the defect.

Answer 252

Malrotation of the viscera is a recognised association and may require surgical correction at the same procedure(favouring an abdominal approach).

Answer 253

In infants that have severe respiratory compromise

Answer 254

Location Around oesophageal hiatus. Incidence May occur in middle age people Aetiology Weak musculature around the oesophageal opening in the diaphragm Types (1) Sliding(hiatal) (2) Para-oesophageal

Answer 255

Around oesophageal hiatus.

Answer 256

May occur in middle age people

Answer 257

Weak musculature around the oesophageal opening in the diaphragm

Answer 258

(1)Sliding(hiatal) (2)Para-oesophageal

Answer 259

**.**Definition:Comprises 12 pairs **.**Shape:Triangular **.**Origin:Tip of transverse process of C7 and T1-T11vertebrae **.**Insertion:Rib below **.**Nerve supply:Posterior rami of thoracic spinal nerves **.**Action:(1)Elevate the ribs (2) Their role on repiration is questionable (3) Possibly proprioception

Answer 260

Comprises 12 pairs

Answer 261

Triangular

Answer 262

Tip of transverse process of C7 and T1-T11 vertebrae

Answer 263

Posterior rami of thoracic spinal nerves

Answer 264

(1) Elevate the ribs (2) Their role on repiration is questionable (3) Possibly proprioception

Answer 265

.Types:(1)Serratus posterior superior (2)Serratus posterior inferior .Features:(1)Thin (2)Flat .Location:Comprise the intermedite layer of muscles of the back .Function:(1)Traditionally-These muscles have been described as respiratory muscles because of their alignments. (2)Recently-However,more recent work suggests both muscles may have proprioceptive functions rather than motor functions.

Answer 266

(1)Serratus posterior superior (2)Serratus posterior inferior

Answer 267

(1)Thin (2)Flat

Answer 268

Comprise the intermedite layer of muscles of the back

Answer 269

(1)Traditionally-These muscles have been described as respiratory muscles because of their alignments. (2)Recently-However,more recent work suggests both muscles may have proprioceptive functions rather than motor functions.

Answer 270

.Origin:(1)Lower cervical spines (2)Upper thoracic spines .Direction of fibres:Passes downward and laterally .Insertion:Upper ribs .Nerve supply:Adjacent intercostal nerves .Action:(1)Inspiration by elavating the ribs (2)Proprioception

Answer 271

(1)Lower cervical spines (2)Upper thoracic spines

Answer 272

Passes downward and laterally

Answer 273

Upper ribs

Answer 274

Adjacent intercostal nerves

Answer 275

(1)Inspiration by elavating the ribs (2)Proprioception

Answer 276

.Origin:(1)Upper lumbar spines (2)Lower thoracic spines .Direction of fibres:Passes upward and laterally .Insertion:Lower ribs .Nerve supply:Adjacent intercostal nerve .Action:(1)Expiration by depressing the ribs (2)Proprioception

Answer 277

(1)Upper lumbar spines (2)Lower thoracic spines

Answer 278

Passes upward and laterally

Answer 279

Lower ribs

Answer 280

Adjacent intercostal nerve

Answer 281

(1)Expiration by depressing the ribs (2)Proprioception

Answer 282

***_1st/THE AORTIC OPENING(ATA in T12)_***.Definition:Notice that the aortic opening is not a true opening within the diaphragm.Rather,it is a gap behind the posterior margin of the diaphragm . .Location:(1)Lies anterior to the body of the 12th thoracic vertebra(T12) (2)Between the crura (3)Midline behind median arcuate ligament .It transmits from Lt to Rt:(1)Abdominal aorta (Mnemonic:ATA) (2)Azygos vein (3)Thoracic duct * **_2nd/THE OESOPHAGEAL OPENING(LOLO2 in T10)_***.Location:(1)Lies at the level of the 10th thoracic vertebra(T10) (2) In a sling of muscle fibres derived from the Rt crus (3) 1 inch to the Lt inside Rt crus .It transmits the: (1)Oesophagus (Mnemonic:LOLO2) (2)2(Rt and Lt)vagi (3) Oesophageal branches of the Lt gastric vessels (4) Lymphatics from the lower 1/3rd of the oesophagus ***_3rd/THE CAVAL OPENING(LIT in T8)_***.Location:(1)Lies at the level of the 8th thoracic vertebra(T8) (2)In the central tendon (3)1 inch to the Rt inside central tendon .It transmits the: (1)Inferior vena cava(IVC) (Mnemonic:LIT) (2)Terminal branches of the Rt phrenic nerve (3)Lymphatic vessels ***_4th/IN ADDITION TO THESE OPENINGS_*** (1) The sympathetic splanchnic nerves:Pierce the crura. (2) The sympathetic trunk:Pass posterior to the medial arcuate ligament on each side. (3) The superior epigastric vessels:Pass between the sternal and costal origins of the diaphragm on each side

Answer 283

***_THE AORTIC OPENING(ATA in T12)_*** .Definition:Notice that the aortic opening is not a true opening within the diaphragm.Rather,it is a gap behind the posterior margin of the diaphragm . .Location:(1)Lies anterior to the body of the 12th thoracic vertebra(T12) (2)Between the crura (3)Midline behind median arcuate ligament .It transmits from Lt to Rt:(1)Abdominal aorta (Mnemonic:ATA) (2)Azygos vein (3)Thoracic duct

Answer 284

Notice that the aortic opening is not a true opening within the diaphragm.Rather,it is a gap behind the posterior margin of the diaphragm .

Answer 285

(1) Lies anterior to the body of the 12th thoracic vertebra(T12). (2) Between the crura. (3) Midline behind median arcuate ligament

Answer 286

It transmits from Lt to Rt(ATA): (1) Abdominal aorta (2) Azygos vein (3) Thoracic duct

Answer 287

* **_THE OESOPHAGEAL OPENING(LOLO2 in T10)_***.Location:(1)Lies at the level of the 10th thoracic vertebra(T10) (2) In a sling of muscle fibres derived from the Rt crus (3) 1 inch to the Lt inside Rt crus .It transmits the: (1)Oesophagus (Mnemonic:LOLO2) (2)2(Rt and Lt)vagi (3) Oesophageal branches of the Lt gastric vessels (4) Lymphatics from the lower 1/3rd of the oesophagus

Answer 288

(1) Lies at the level of the 10th thoracic vertebra(T10) (2)In a sling of muscle fibres derived from the Rt crus (3) 1 inch to the Lt inside Rt crus

Answer 289

.It transmits the: (1)Oesophagus (Mnemonic:LOLO2) (2)2(Rt and Lt)vagi (3) Oesophageal branches of the Lt gastric vessels (4) Lymphatics from the lower 1/3rd of the oesophagus

Answer 290

***_THE CAVAL OPENING(LIT in T8)_*** .Location:(1)Lies at the level of the 8th thoracic vertebra(T8) (2)In the central tendon (3)1 inch to the Rt inside central tendon .It transmits the: (1)Inferior vena cava(IVC) (Mnemonic:LIT) (2)Terminal branches of the Rt phrenic nerve (3)Lymphatic vessels

Answer 291

(1) Lies at the level of the 8th thoracic vertebra(T8) (2) In the central tendon (3) 1 inch to the Rt inside central tendon

Answer 292

It transmits the: (1)Inferior vena cava(IVC) (Mnemonic:LIT) (2)Terminal branches of the Rt phrenic nerve (3)Lymphatic vessels

Answer 293

(1) The sympathetic splanchnic nerves:Pierce the crura. (2) The sympathetic trunk:Pass posterior to the medial arcuate ligament on each side. (3) The superior epigastric vessels:Pass between the sternal and costal origins of the diaphragm on each side

Answer 294

.Origin: These nerves are the anterior rami of the first 11 thoracic spinal nerves. .Course: (1)Each intercostal nerve enters an intercostal space between the parietal pleura and the posterior intercostal membrane. (2)It then runs forward inferiorly:(a)to the intercostal vessels in the subcostal groove of the corresponding rib. (b)between the innermost intercostal and internal intercostal muscles .Distribution: I)The 1st 6 nerves -are distributed within their intercostal spaces. -The 1st intercostal nerve:(a)joins the brachial plexus by a large branch that is equivalent to the lateral cutaneous branch of typical intercostal nerves. (b)the remainder of the 1st intercostal nerve +is small +and an anterior cutaneous branch does not exist. -The 2nd intercostal nerve:(a)Course:Joins the medial cutaneous nerve of the arm by a large branch named the Intercostobrachial nerve, which is equivalent to the lateral cutaneous branch of other nerves. (b)Function:(1)Supplies the skin of the +armpit +upper medial side of the arm. (2)In coronary artery disease, pain is referred along this nerve to the medial side of the arm. II)The 7th-11th intercostal nerves(peritoneal sensory branches) -Supply the:(1)skin and the parietal peritoneum covering the outer and inner surfaces of the abdominal wall, respectively, plus the (2)anterolateral abdominal wall muscles (which include the external oblique, internal oblique, transversus abdominls, and rectus abdominis muscles). -Run to the parietal peritoneum. -Distribution:(a)The 7th to 9th intercostal nerves leave the anterior ends of their intercostal spaces by passing deep to the costal cartilages therefore,leaving the thoracic wall to enter the anterior abdominal to supply dermatomes in the anterior abdominal wall,muscles....etc. -The 10th and 11th nerves:pass directly into the abdominal wall .Function: I)supply the entire thoracic wall. II)An Intercostal nerve not only supplies areas of skin but also supplies the ribs, costal cartilages, intercostal muscles, and parietal pleura lining the intercostal space. III)With the exceptions noted,the firsts intercostal nerves supply the (1)skin and the parietal pleura covering the outer and inner surfaces of each intercostal space, respectively. PLUS (2) the intercostal muscles of each intercostal space and (3) the levatores costarum and (4) serratus posterior muscles .Branches: • **Rami communicants:**connect the intercostal nerve to a ganglion of the sympathetic trunk.The gray and white rami are adjacent to one another. • The **collateral branch:**runs forward inferiorly to the main nerve on the upper border of the rib below. • The **lateral cutaneous** **branch:**reaches the skln on the side of the chest. It divides into an anterior and a posterior branch. • The **anterior cutaneous branch:**which is the terminal portion of the main trunk, reaches the skin near the midline. It divides into a medial and a lateral branch. • **Muscular branches:**run to the intercostal muscles. • **Pleural sensory branches:**go to the parietal pleura. • **Peritoneal sensory branches**(7th to11th intercostal nerves only):run to the parietal peritoneum.

Answer 295

I)supply the entire thoracic wall. II)With the exceptions noted,the firsts intercostal nerves supply the (1)skin and the parietal pleura covering the outer and inner surfaces of each intercostal space, respectively. PLUS (2) the intercostal muscles of each intercostal space and (3) the levatores costarum and (4) serratus posterior muscles

Answer 296

These nerves are the anterior rami of the first 11 thoracic spinal nerves.

Answer 297

(1)Each intercostal nerve enters an intercostal space between the parietal pleura and the posterior intercostal membrane. (2)It then runs forward inferiorly:(a)to the intercostal vessels in the subcostal groove of the corresponding rib. (b)between the innermost intercostal and internal intercostal muscles

Answer 298

I)The 1st 6 nerves -are distributed within their intercostal spaces. -The 1st intercostal nerve:(a)joins the brachial plexus by a large branch that is equivalent to the lateral cutaneous branch of typical intercostal nerves. (b)the remainder of the 1st intercostal nerve +is small +and an anterior cutaneous branch does not exist. -The 2nd intercostal nerve:(a)Course:Joins the medial cutaneous nerve of the arm by a large branch named the Intercostobrachial nerve, which is equivalent to the lateral cutaneous branch of other nerves. (b)Function:(1)Supplies the skin of the +armpit +upper medial side of the arm. (2)In coronary artery disease, pain is referred along this nerve to the medial side of the arm. -With the exceptions noted,the firsts intercostal nerves supply the (1)skin and the parietal pleura covering the outer and inner surfaces of each intercostal space, respectively. PLUS (2)the intercostal muscles of each intercostal space and (3)the levatores costarum and (4) serratus posterior muscles II)The 7th-11th intercostal nerves(peritoneal sensory branches) -Supply the:(1)skin and the parietal peritoneum covering the outer and inner surfaces of the abdominal wall, respectively, plus the (2)anterolateral abdominal wall muscles (which include the external oblique, internal oblique, transversus abdominls, and rectus abdominis muscles). -Run to the parietal peritoneum. -Distribution:(a)The 7th to 9th intercostal nerves leave the anterior ends of their intercostal spaces by passing deep to the costal cartilages therefore,leaving the thoracic wall to enter the anterior abdominal to supply dermatomes in the anterior abdominal wall,muscles....etc. -The 10th and 11th nerves:pass directly into the abdominal wall

Answer 299

-are distributed within their intercostal spaces. -The 1st intercostal nerve:(a)joins the brachial plexus by a large branch that is equivalent to the lateral cutaneous branch of typical intercostal nerves. (b)the remainder of the 1st intercostal nerve +is small +and an anterior cutaneous branch does not exist. -The 2nd intercostal nerve:(a)Course:Joins the medial cutaneous nerve of the arm by a large branch named the Intercostobrachial nerve, which is equivalent to the lateral cutaneous branch of other nerves. (b)Function:(1)Supplies the skin of the +armpit +upper medial side of the arm. (2)In coronary artery disease, pain is referred along this nerve to the medial side of the arm. -With the exceptions noted,the firsts intercostal nerves supply the (1)skin and the parietal pleura covering the outer and inner surfaces of each intercostal space, respectively. PLUS (2) the intercostal muscles of each intercostal space and (3) the levatores costarum and (4) serratus posterior muscles

Answer 300

.Course(a)joins the brachial plexus by a large branch that is equivalent to the lateral cutaneous branch of typical intercostal nerves. (b)the remainder of the 1st intercostal nerve +is small +and an anterior cutaneous branch does not exist. .Function:With the exceptions noted,the firsts intercostal nerves supply the (1)skin and the parietal pleura covering the outer and inner surfaces of each intercostal space, respectively. PLUS (2) the intercostal muscles of each intercostal space and (3) the levatores costarum and (4) serratus posterior muscles

Answer 301

(a)joins the brachial plexus by a large branch that is equivalent to the lateral cutaneous branch of typical intercostal nerves. (b)the remainder of the 1st intercostal nerve +is small +and an anterior cutaneous branch does not exist.

Answer 302

With the exceptions noted,the firsts intercostal nerves supply the (1)skin and the parietal pleura covering the outer and inner surfaces of each intercostal space, respectively. PLUS (2) the intercostal muscles of each intercostal space and (3) the levatores costarum and (4) serratus posterior muscles

Answer 303

(a)Course:Joins the medial cutaneous nerve of the arm by a large branch named the intercostobrachial nerve, which is equivalent to the lateral cutaneous branch of other nerves. (b)Function:(1)Supplies the skin of the +armpit +upper medial side of the arm. (2)In coronary artery disease, pain is referred along this nerve to the medial side of the arm.

Answer 304

Joins the medial cutaneous nerve of the arm by a large branch named the intercostobrachial nerve, which is equivalent to the lateral cutaneous branch of other nerves.

Answer 305

(1)Supplies the skin of the +armpit +upper medial side of the arm. (2)In coronary artery disease, pain is referred along this nerve to the medial side of the arm.

Answer 306

• Rami communicants:connect the intercostal nerve to a ganglion of the sympathetic trunk.The gray and white rami are adjacent to one another. • The collateral branch:runs forward inferiorly to the main nerve on the upper border of the rib below. • The lateral cutaneous branch:reaches the skln on the side of the chest. It divides into an anterior and a posterior branch. • The anterior cutaneous branch:which is the terminal portion of the main trunk, reaches the skin near the midline. It divides into a medial and a lateral branch. • Muscular branches:run to the intercostal muscles. • Pleural sensory branches:go to the parietal pleura. • Peritoneal sensory branches(7th to11th intercostal nerves only):run to the parietal peritoneum.

Answer 307

The anterior ramus of the 12th thoracic nerve lies in the abdomen and runs forward in the abdominal wall as the subcostal nerve.

Answer 308

**1st/The skin on the anterior surface of the chest wall** I)Above the level of the sternal angle:The supra clavicular nerve(C3 and 4)provide the cutaneous innervation. II)Below the level of the sternal angle:The anterior and lateral cutaneous branches of the intercostal nerves supply oblique bands of skin in regular sequence. **2nd/The skin on the posterior surface of the chest wall** Supplied by the posterior rami of the spinal nerves

Answer 309

the 7th to 11th Intercostal nerves leave the thoracic wall and enter the anterior abdominal wall to supply dermatomes on the anterior abdominal wall,muscles of the anterior abdominal wall, and parietal peritoneum. This latter fact is of great clinical importance because it means that disease in the thoracic wall may be revealed as pain in a dermatome that extends across the costal margin Into the anterior abdomfnal. wall. For example, a pulmonary thromboembollsm or pneumoniawith pleurisy Involving the costal parietal pleura could give rise to abdominal pain and tenderness and rigidity of the abdominal musculature. The abdominal pain in these instances is called **referred pain**. In addition, the 7th to 11th intercostal nerves supply the skin and the parietal peritoneum covering the outer and lnner surfaces of the abdominal wall, respectively, plus the anterolateral abdominal wall muscles (which include the external oblique, internal oblique, transver- sus abdominls, and rectus abdominis muscles).

Answer 310

Other names Shingles .Incidence Is a relatively common condition. The condition occurs most frequently in patients older than 50 years. .Aetiology caused by the reactivation of the latent varicella-zoster virus in a patient who has previously had chickenpox. .Pathophysiology The lesion is seen as an inflammation and degeneration of the sensory neurons in a cranial or spinal nerve with the formation of vesicles and inflammation of the skin. .C/P In the thorax, the first symptom is a band of dermatomal pain in the distribution of the sensory neurons in a thoracic spinal nerve,followed in a few days by a skin eruption.

Answer 311

Related anatomy The skin and the parietal pleura cover the outer and inner surfaces of each intercostal space, respectively. The 7th to 11th Intercostal nerves supply the skin and the parietal peritoneum covering the outer and inner surfaces of the anterolateral abdominal wall, respectively. Therefore, an intercostal nerve block will also anesthetize these areas. In addition,the periosteum of the adjacent ribs is anaesthetised. Indications (1) For repair of lacerations of the thoracic and abdominal walls (2) For relief of pain in rib fractures (3) To allow pain-free respiratory movements. (4) To produce analgesia of the anterior and lateral thoracic and abdominal walls Procedure (1)the intercostal nerve should be blocked before the lateral cutaneous branch arises at the mid axillary line. (2)The ribs may be identified by counting down from the second (opposite the sternal angle) or up from the 12th. (3)The needle is directed toward the rib near the lower border and (4)Th tip of the needle comes to rest near the subcostal groove, where the local anesthetic is infiltrated around the nerve. (5)Remember that the order of structures lying in the neurovascular bundle from above downward is intercostal vein, artery, and nerve and that these structures are situated between the posterior intercostal membrane of the internal intercostal muscle and the parietal pleura.Furthermore, laterally, the nerve lies between the internal intercostal muscle and the innermost intercostal muscle Anatomy of Complications Complications Include pneumothorax and hemorrhage. I)Pneumothorax can occur if the needle point misses the subcostal groove and penetrates too deeply through the parietal pleura. II)Hemorrhage +Incidence:This is a common condition. +Atiology:Is caused by the puncture of the intercostal blood vessels. so aspiration should always be performed before injecting the anesthetic. +Complication:A small hematoma may result.

Answer 312

The subclavian artery,axillary artery,and thoracic aorta supply the thoracic walls. I)The subclavian artery-provides blood through its:(1)superior intercostal artery (2)internal thoracic artery II)The axillary artery-supplies via its:(1)superior thoracic artery (2)lateral thoracic artery III)The thoracic aorta-gives off:(1)posterior intercostal artery (2)subcostal artery

Answer 313

.Function The Internal thoracic artery supplies the anterior wall of the body from the clavicle to the umbilicus. .Origin It Is a branch of the first part of the subclavian artery in the neck. .Course (1) It descends vertically on the pleura behind the costal cartilages, a fingerbreadth lateral to the sternum. and (2) ends in the sixth intercostal space by dividing into the:(a)superior epigastric artery (b) musculophrenic artery .Branches (1)**Two anterior intercostal arteries:**supply the upper six intercostal spaces. (2)**Perforating arteries:**accompany the terminal branches of the corresponding intercostal nerves. (3)**The pericardiophrenic artery:**accompanies the phrenic nerve and supplies the pericardium. (4)**Mediastinal arteries:**supply the contents of the anterior mediastinum(e.g.,the thymus) (5)**The superior epigastr****ic artery**:enters the rectus sheath of the anterior abdominal wall and supplies the rectus muscle as far as the umbilicus. (6)**The musculophrenic artery:**runs around the costal margin of the diaphragm and supplies the lower intercostal spaces and the diaphragm.

Answer 314

The Internal thoracic artery supplies the anterior wall of the body from the clavicle to the umbilicus.

Answer 315

It Is a branch of the first part of the subclavian artery in the neck.

Answer 316

(1) It descends vertically on the pleura behind the costal cartilages, a fingerbreadth lateral to the sternum. and (2) ends in the sixth intercostal space by dividing into the:(a)superior epigastric artery (b) musculophrenic artery

Answer 317

(1)Two anterior intercostal arteries:supply the upper six intercostal spaces. (2)Perforating arteries:accompany the terminal branches of the corresponding intercostal nerves. (3)The pericardiophrenic artery:accompanies the phrenic nerve and supplies the pericardium. (4)Mediastinal arteries:supply the contents of the anterior mediastinum(e.g.,the thymus) (5)The superior epigastric artery:enters the rectus sheath of the anterior abdominal wall and supplies the rectus muscle as far as the umbilicus. (6)The musculophrenic artery:runs around the costal margin of the diaphragm and supplies the lower intercostal spaces and the diaphragm.

Answer 318

The internal thoracic vein accompanies the internal thoracic artery and drains into the brachiocephalic vein on each side.

Answer 319

.Features I)Each intercostal space contains:(1)a large single posterior intercostal artery and (2)two small anterior intercostal arteries II)Each intercostal artery gives off branches to the:(1)muscles, (2)skin, and (3)parietal pleura. III)The branches to the superficial structures are particularly large in the breast region in females. IV) The anterior and posterior intercostal arteries typically anastomose with one another at approximately the costochondral junctions. .classification 1st/The posterior intercostal arteries (1)The posterior intercostal arteries of the first two spaces:are branches from the superior intercostal artery, a branch of the costocervical trunk of the subclavian artery. (2)The posterior intercostal arteries of the lower nine spaces:are branches of the descending thoracic aorta. 2nd/The anterior intercostal arteries (1)The anterior intercostal arteries of the first six spaces:are branches of the internal thoracic artery, which arises from the first part of the subclavian artery. (2)The anterior intercostal arteries of the lower spaces:are branches of the musculophrenic artery, one of the terminal branches of the internal thoracic artery.

Answer 320

I)Each intercostal space contains:(1)a large single posterior intercostal artery and (2)two small anterior intercostal arteries II)Each intercostal artery gives off branches to the:(1)muscles, (2)skin, and (3)parietal pleura. III)The branches to the superficial structures are particularly large in the breast region in females. IV) The anterior and posterior intercostal arteries typically anastomose with one another at approximately the costochondral junctions.

Answer 321

Large and single

Answer 322

Small and two

Answer 323

Costochondral junctions

Answer 324

.classification 1st/The posterior intercostal arteries (1)The posterior intercostal arteries of the first two spaces:are branches from the superior intercostal artery, a branch of the costocervical trunk of the subclavian artery. (2)The posterior intercostal arteries of the lower nine spaces:are branches of the descending thoracic aorta. 2nd/The anterior intercostal arteries (1)The anterior intercostal arteries of the first six spaces:are branches of the internal thoracic artery, which arises from the first part of the subclavian artery. (2)The anterior intercostal arteries of the lower spaces:are branches of the musculophrenic artery, one of the terminal branches of the internal thoracic artery.

Answer 325

(1)The posterior intercostal arteries of the first two spaces:are branches from the superior intercostal artery, a branch of the costocervical trunk of the subclavian artery. (2)The posterior intercostal arteries of the lower nine spaces:are branches of the descending thoracic aorta.

Answer 326

branches from the superior intercostal artery, a branch of the costocervical trunk of the subclavian artery.

Answer 327

are branches of the descending thoracic aorta.

Answer 328

(1)The anterior intercostal arteries of the first six spaces:are branches of the internal thoracic artery, which arises from the first part of the subclavian artery. (2)The anterior intercostal arteries of the lower spaces:are branches of the musculophrenic artery, one of the terminal branches of the internal thoracic artery.

Answer 329

(1)The anterior intercostal arteries of the first six spaces:are branches of the internal thoracic artery, which arises from the first part of the subclavian artery. (2)The anterior intercostal arteries of the lower spaces:are branches of the musculophrenic artery, one of the terminal branches of the internal thoracic artery.

Answer 330

are branches of the internal thoracic artery, which arises from the first part of the subclavian artery.

Answer 331

are branches of the musculophrenic artery, one of the terminal branches of the internal thoracic artery.

Answer 332

Each intercostal artery gives off branches to the:(1)muscles, (2) skin, and (3) parietal pleura.

Answer 333

The branches to the superficial structures are particularly large in the breast region in females.

Answer 334

.Feature The intercostal veins correspond to the arteries. .Drainage (1) The corresponding posterior intercostal veins drain posteriorly into the azygos or hemiazygos veins (2) The anterior intercostal veins drain anteriorly into the internal thoracic and musculophrenic veins.

Answer 335

The intercostal veins correspond to the arteries.

Answer 336

(1) The corresponding posterior intercostal veins drain posteriorly into the azygos or hemiazygos veins (2) The anterior intercostal veins drain anteriorly into the internal thoracic and musculophrenic veins.

Answer 337

The corresponding posterior intercostal veins drain posteriorly into the azygos or hemiazygos veins

Answer 338

The anterior intercostal veins drain anteriorly into the internal thoracic and musculophrenic veins.

Answer 339

(1)The anterior intercostal arteries(branches of the subclavian artery via the internal thoracic and musculophrenic arteries) and the lower nine posterior intercostal arteries (branches of the thoracic aorta) typically anastomose with one another at approximately the costochondral junctions. (2)These important connections create collateral circulatory routes that potentially allow blood flow to bypass obstructions in the thoracic aorta or the proximal part of the subclavian artery. (3)These anastomoses are notably prominent in circumventing the constriction present in poatductal coarctation of the aorta.

Answer 340

(1)In patients with occlusive coronary disease caused by atherosclerosis, the diseased arterial segment can be bypassed by inserting a graft. (2)The graft most commonly used is the great saphenous vein of the leg. (3) However, the myocardium can be revascularized in some patients by surgically mobilizing one of the internal thoracic arteries and joining its distal cut end to a coronary artery.

Answer 341

I)The lymph drainage of the skin of the anterior chest wall:passes to the anterior axillary lymph nodes II)The lymph drainage of the skin of the posterior chest wall:passes to the posterior axillary nodes. III)The lymph drainage of the intercostal spaces:passes forward to the internal thoracic nodes, situated along the internal thoracic artery, and posteriorly to the posterior Intercostal nodes and the para-aortic nodes in the posterior mediastinum.

Answer 342

passes to the anterior axillary lymph nodes

Answer 343

passes to the posterior axillary nodes.

Answer 344

(1) passes forward to the internal thoracic nodes, situated along the internal thoracic artery, and (2) posteriorly to the posterior intercostal nodes and the para-aortic nodes in the posterior mediastinum.

Answer 345

.Definition Needle thoracostomy is creating and maintaining an opening into the thoracic cavity by using a needle. .Indications (1) tension pneumothorax (air in the pleural cavity under pressure) (2) to drain fluid (blood or pus) away from the pleural cavity to allow the lung to reexpand. (3) to withdraw a sample of pleural fluid for microbiologic examination. .Technique I)Anterior approach:(1)The patient is in the supine position. (2)The sternal angle is identified, and then, (3)The second costal cartilage, the second rib, and the second intercostal space are found in the midclavicular line. II)Lateral approach:(1)The patient is lying on the lateral side. (2)The second intercostal space is identified as above, but the anterior axillary line is used. (3)The skin is prepared in the usual way, and (4)A local anesthetic is introduced along the course of the needle above the upper border of the third rib. (5) The thoracostomy needle will pierce the following structures as it passes through the chest wall (a) skin, (b) superficial fascia (in the anterior approach, the pectoral muscles are then penetrated), (c) serratus anterior muscle, (d) external intercostal muscle, (e) internal intercostal muscle, (f) innermost intercostal muscle, (g) endothoracic fascia, and (h) parietal pleura. (6)The needle should be kept close to the upper border of the third rib to avoid injuring the intercostal vessels and nerve In the subcostal groove.

Answer 346

Needle thoracostomy is creating and maintaining an opening into the thoracic cavity by using a needle.

Answer 347

(1) tension pneumothorax (air in the pleural cavity under pressure) (2) to drain fluid (blood or pus) away from the pleural cavity to allow the lung to reexpand. (3) to withdraw a sample of pleural fluid for microbiologic examination

Answer 348

I)Anterior approach:(1)The patient is in the supine position. (2)The sternal angle is identified, and then, (3)The second costal cartilage, the second rib, and the second intercostal space are found in the midclavicular line. II)Lateral approach:(1)The patient is lying on the lateral side. (2)The second intercostal space is identified as above, but the anterior axillary line is used. (3)The skin is prepared in the usual way, and (4)A local anesthetic is introduced along the course of the needle above the upper border of the third rib. (5) The thoracostomy needle will pierce the following structures as it passes through the chest wall (a) skin, (b) superficial fascia (in the anterior approach, the pectoral muscles are then penetrated), (c) serratus anterior muscle, (d) external intercostal muscle, (e) internal intercostal muscle, (f) innermost intercostal muscle, (g) endothoracic fascia, and (h) parietal pleura. (6)The needle should be kept close to the upper border of the third rib to avoid injuring the intercostal vessels and nerve In the subcostal groove.

Answer 349

(1) The patient is in the supine position. (2) The sternal angle is identified, and then, (3) The second costal cartilage, the second rib, and the second intercostal space are found in the midclavicular line.

Answer 350

(1)The patient is lying on the lateral side. (2)The second intercostal space is identified as above, but the anterior axillary line is used. (3)The skin is prepared in the usual way, and (4)A local anesthetic is introduced along the course of the needle above the upper border of the third rib. (5)The thoracostomy needle will pierce the following structures as it passes through the chest wall (a) skin, (b) superficial fascia (in the anterior approach, the pectoral muscles are then penetrated), (c) serratus anterior muscle, (d) external intercostal muscle, (e) internal intercostal muscle, (f) innermost intercostal muscle, (g) endothoracic fascia, and (h) parietal pleura. (6)The needle should be kept close to the upper border of the third rib to avoid injuring the intercostal vessels and nerve in the subcostal groove.

Answer 351

(a) skin, (b) superficial fascia (in the anterior approach, the pectoral muscles are then penetrated), (c) serratus anterior muscle, (d) external intercostal muscle, (e) internal intercostal muscle, (f) innermost intercostal muscle, (g) endothoracic fascia, and (h) parietal pleura.

Answer 352

.Insertion site The preferred insertion site for a tube thoracostomy is the fourth or fifth intercostal space at the anterior axillary line. The tube is introduced through a small incision. .Related anatomy (1)The neurovascular bundle changes its relationship to the ribs as it passes forward in the intercostal space. (2)In the most posterior part of the space, the bundle lies in the middle of the intercostal space. (3)As the bundle passes forward to the rib angle, it becomes closely related to the costal groove on the lower border of the rib above and maintains that position as it courses forward. (4)The introduction of a thoracostomy tube or needle through the lower intercostal spaces is possible provided that the presence of the domes of the diaphragm is remembered as they curve upward into the rib cage as far as the fifth rib (higher on the right). Avoid damaging the diaphragm and entering the peritoneal cavity and injuring the liver, spleen, or stomach.

Answer 353

The preferred insertion site for a tube thoracostomy is the fourth or fifth intercostal space at the anterior axillary line. The tube is introduced through a small incision.

Answer 354

(1)The neurovascular bundle changes its relationship to the ribs as it passes forward in the intercostal space. (2)In the most posterior part of the space, the bundle lies in the middle of the intercostal space. (3)As the bundle passes forward to the rib angle, it becomes closely related to the costal groove on the lower border of the rib above and maintains that position as it courses forward. (4)The introduction of a thoracostomy tube or needle through the lower intercostal spaces is possible provided that the presence of the domes of the diaphragm is remembered as they curve upward into the rib cage as far as the fifth rib (higher on the right). Avoid damaging the diaphragm and entering the peritoneal cavity and injuring the liver, spleen, or stomach.

Answer 355

.Definition Thoracotomy is making an incision through the thoracic wall into the pleural space. .Indication This may be a lifesaving procedure in patients with penetrating chest wounds with uncontrolled intrathoracic hemorrhage. .Technique (1)After preparing the skin in the usual way, the physician makes an incision over the fourth or fifth intercostal space,extending from the lateral margin of the sternum to the anterior axillary line. (2)Whether to make a right or left Incision depends on the site of the injury. (3)The chest should be entered from the left side for access to the heart and aorta. (4)The following tissues will be incised: (a) skin, (b) subcutaneous tissue, (c) serratus anterior and pectoral muscles, (d) external intercostal muscle and anterior intercostal membrane, (e) internal intercostal muscle, (f) innermost intercostal muscle, (g) endothoracic fascia, and (h) parietal pleura. (5)Avoid the: (a)internal thoracic artery-which runs vertically downward behind the costal cartilages about a fingerbreadth lateral to the margin of the sternum, and the (b)intercostal vessels and nerve-which extend forward in the subcostal groove in the upper part of the intercostal space.

Answer 356

Thoracotomy is making an incision through the thoracic wall into the pleural space.

Answer 357

This may be a lifesaving procedure in patients with penetrating chest wounds with uncontrolled intrathoracic hemorrhage.

Answer 358

(1)After preparing the skin in the usual way, the physician makes an incision over the fourth or fifth intercostal space,extending from the lateral margin of the sternum to the anterior axillary line. (2)Whether to make a right or left Incision depends on the site of the injury. (3)The chest should be entered from the left side for access to the heart and aorta. (4)The following tissues will be incised: (a) skin, (b) subcutaneous tissue, (c) serratus anterior and pectoral muscles, (d) external intercostal muscle and anterior intercostal membrane, (e) internal intercostal muscle, (f) innermost intercostal muscle, (g) endothoracic fascia, and (h) parietal pleura. (5)Avoid the: (a)internal thoracic artery-which runs vertically downward behind the costal cartilages about a fingerbreadth lateral to the margin of the sternum, and the (b)intercostal vessels and nerve-which extend forward in the subcostal groove in the upper part of the intercostal space.

Answer 359

After preparing the skin in the usual way, the physician makes an incision over the fourth or fifth intercostal space,extending from the lateral margin of the sternum to the anterior axillary line.

Answer 360

Whether to make a right or left Incision depends on the site of the injury. The chest should be entered from the left side for access to the heart and aorta.

Answer 361

The chest should be entered from the left side for access to the heart and aorta.

Answer 362

(a) skin, (b) subcutaneous tissue, (c) serratus anterior and pectoral muscles, (d) external intercostal muscle and anterior intercostal membrane, (e) internal intercostal muscle, (f) innermost intercostal muscle, (g) endothoracic fascia, and (h) parietal pleura.

Answer 363

(a)internal thoracic artery-which runs vertically downward behind the costal cartilages about a fingerbreadth lateral to the margin of the sternum, and (b)intercostal vessels and nerve-which extend forward in the subcostal groove in the upper part of the intercostal space.

Answer 364

Certain anatomic and physiologic changes take place in the thorax with advancing years: • The rib cage becomes more rigid and loses its elasticity as the result of calcification and even ossification of the costal cartilages. This also alters their usual radiographic appearance. • The stooped posture (kyphosis), so often seen in the old because of degeneration of the intervertebral discs and/ or bodies, decreases the chest capacity. • Disuse atrophy of the thoracic and abdominal muscles can result in poor respiratory movements. • Degeneration of the elastic tissue in the lungs and bronchi results in impairment of the movement of expiration. These changes, when severe, diminish the efficiency of respiratory movements and impair the ability of the individual to withstand respiratory disease.

Answer 365

(1) The suprasternal notch is the superior margin of the manubrium sterni (2) is easily felt between the prominent medial ends of the clavicles in the midline. (3) It lies opposite the lower border of the body of the second thoracic vertebra

Answer 366

(1)The sternal angle (angle of Louis) is the angle made between the manubrium and the body of the sternum. (2)It lies opposite the intervertebral disc between the fourth and fifth thoracic vertebrae. (3)When examining the chest from in front, the sternal angle is an important landmark (4)The position of the sternal angle can easily be felt and is often seen as a transverse ridge.(5)The finger moved to the right or to the left will pass directly onto the second costal cartilage and then the second rib. All other ribs may be counted from this point. (6)Occasionally in a very muscular male, large pectoral muscles may obscure the ribs and intercostal spaces. In these cases, it may be easier to count up from the 12th rib.

Answer 367

(1) The xiphisternal joint is the joint between the xiphoid process of the sternum and the body of the sternum. (2) It lies opposite the body of the ninth thoracic vertebra

Answer 368

(1) The subcostal angle is situated at the inferior end of the sternum, (2) between the sternal attachments of the seventh costal cartilages

Answer 369

.Definition The costal margin is the lower boundary of the thorax .Formation. (1) is formed by the cartilages of the 7th, 8th, 9th, and 10th ribs and the ends of the 11th and 12th cartilages (see Figs. 4.19 (2) The lowest part of the costal margin:(a)is formed by the 10th rib (b) lies at the level of the third lumbar vertebra.

Answer 370

(1) In the male, the nipple usually lies in the fourth intercostal space about 4 in. (10 cm) from the midline. (2) In the female, its position is not constant. (3) However, the T4 dermatome always crosses the nipple in both sexes regardless of the form of the breast.

Answer 371

(1)The first rib lies deep to the clavicle and cannot be palpated. (2)Pressing the fingers upward into the axilla and drawing them downward over the lateral surface of the chest wall can allow feeling the lateral surfaces of the remaining ribs. (3)The 12th rib can be used to identify a particular rib by counting from below. However, in some individuals, the 12th rib is very short and difficult to feel. For this reason, an alternative method may be used to identify ribs by first palpating the sternal angle and the second costal cartilage.The 12th rib can usually be felt from behind, but in some obese persons, this may prove difficult.

Answer 372

(1)The central tendon of the diaphragm lies directly behind the xiphisternal joint. (2)In the midrespiratory position,the summit of the right dome of the diaphragm arches upward as far as the upper border of the fifth rib in the midclavicular line, but the left dome only reaches as far as the lower border of the fifth rib.

Answer 373

(1) In the male, the nipple usually lies in the fourth inter- costal space about 4 in. (10 em) from the midline. (2) In the female, its position is not constant. (3) However, the T4 dermatome always crosses the nipple in both sexes regardless of the form of the breast.

Answer 374

(1)The lower portion of the left ventricle forms the apex of the heart. (2)The apex of the heart being thrust forward against the thoracic wall as the heart contracts causes the apex beat. (the heart is thrust forward with each ventricular contraction because of the ejection of blood from the left ventricle into the aorta; the force of the blood in the aorta tends to cause the curved aorta to straighten slightly, thus pushing the heart forward.) (3)The apex beat can usually be felt by placing the flat of the hand on the chest wall over the heart. After the area of cardiac pulsation has been determined, the apex beat is accurately localized by placing two fingers over the intercostal spaces and moving them until the point of maximum pulsation is found. (4)The apex beat is normally found in the fifth left intercostal space, 3.5 in. (9 em) from the midline. (5)If you have difficulty in finding the apex beat, have the patient lean forward in the sitting position. (6)In a female with pendulous breasts, the examining fingers should gently raise the left breast from below as the intercostal spaces are palpated.

Answer 375

(1)The lower border of the pectoralis major muscle forms the anterior axlllary fold. (2)This can be made to stand out by asking the patient to press a hand hard against the hip. (3)The tendon of the latissimus dorsi muscle as it passes around the lower border of the teres major muscle forms the posterior axillary fold

Answer 376

(1)The spinous processes of the thoracic vertebrae can be palpated in the posterior midline (2)The index finger should be placed on the skin in the midline on the posterior surface of the neck and drawn downward in the nuchal groove. (3)The first spinous process to be felt is that of the seventh cervical vertebrae (vertebra prominens). (4)The overlapping spines of the thoracic vertebrae are below this level. (5)A large ligament, the ligamentum nuchae, covers the spines of the C1 to 6 vertebrae. (6)It should be noted that the tip of a spinous process of a thoracic vertebra lies posterior to the body of the next vertebra below. (7)The scapula (shoulder blade) is flat and triangular in shape and is located on the upper part of the posterior surface of the thorax. The superior angle lies opposite the spine of the second thoracic vertebra. The spine of the scapula is subcutaneous, and the root of the spine lies on a level with the spine of the third thoracic verte- bra. The inferior angle lies on a level with the spine of the seventh thoracic vertebra.

Answer 377

(1) The scapula (shoulder blade) is flat and triangular in shape (2) Is located on the upper part of the posterior surface of the thorax. (3) The superior angle lies opposite the spine of the second thoracic vertebra. (4) The spine of the scapula is subcutaneous, and the root of the spine lies on a level with the spine of the third thoracic vertebra. (5)The inferior angle lies on a level with the spine of the seventh thoracic vertebra.

Answer 378

Several imaginary lines are sometimes used to describe surface locations on the anterior and posterior chest walls: • The midsternalline lies in the median plane over the sternum. • The midclavicular line runs vertically downward from the midpoint of the clavicle. • The anterior axillary line runs vertically downward from the anterior axillary fold. • The posterior axillary line runs vertically downward from the posterior axillary fold. • The midaxillary line runs vertically downward from a point situated midway between the anterior and posterior axillary folds. • The scapular line runs vertically downward on the posterior wall of the thorax, passing through the infe- rior angle of the scapula (arms at the sides)

Answer 379

(1)The trachea extends from the lower border of the cricoid cartilage (opposite the body of the sixth cervical vertebra) in the neck to the level of the sternal angle in the thorax. (2)It commences in the midline and ends just to the right of the midline by dividing into the right and the left principal bronchi. (3)At the root of the neck, it may be palpated in the midline in the suprasternal notch.

Thorax Anatomy-Thoracic wall(Snell's Clinical Anatomy By Regions 10th Edition) Flashcards

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