Thoracic Wall and Pleura Flashcards
(105 cards)
1
Q
what are the bones of the thorax?
A
12 pairs of ribs and associated costal cartialges, 12 thoracic vertebrae and the intervertebral discs between them, the sternum
2
Q
which rib isnt palpable?
A
rib 1
3
Q
what makes up the anterior thoracic wall?
A
the sternum (body and manubrium), xiphoid process
4
Q
what makes up the lateral thoracic wall?
A
rib cage, 3 flat muscles (pectorlais major and minor, subclavius)
5
Q
what makes up the posterior thoracic wall?
A
12 thoracic vertebrae and their IV discs
6
Q
which ribs does the scapula overlie?
A
ribs 2-7
7
Q
what kind of bones are ribs?
A
flat bones
8
Q
what are the 3 types of ribs
A
- True ribs = ribs 1–7
- False ribs = ribs 8, 9, usually 10
- Floating ribs = ribs 11, 12, sometimes 10
9
Q
what is a true rib?
A
a rib which attaches directly to the sternum through their own costal cartialges (aka vertebrosternal ribs)
10
Q
what is a false rib?
A
a rib in which its cartilage is connected to the cartilage of the rib above them — indirect connection with sternum (aka vertebrochondral ribs)
11
Q
what is a floating rib?
A
a rib in which its rudimentary cartilage does not connect even indirectly with the sternum — end in posterior abdominal musculature instead (aka vertebral, free ribs)
12
Q
where does costal cartilage convergence begin?
A
rib 6
13
Q
what does a typical rib consist of?
A
head, neck, tubercle, shaft, costal groove
14
Q
describe the head of a rib
A
- wedge-shaped
- has 2 facets separated by the crest of the head
- 1 facet for articulation with numerically corresponding vertebra and one facet for the above vertebra
15
Q
describe the neck of a rib
A
connects the head with the body at the level of the tubercle
16
Q
describe the tubercle of a rib
A
- located at junction of neck and body
- TUBERCLE OF RIB ATTACHES TO THE TRANSVERSE PROCESS OF THE VERTEBRA
- consists of a smooth articular facet (for articulation with the corresponding transverse process of the vertebra) and a rough nonarticular part (provides attachment for the costotransverse ligament)
17
Q
describe the body of a rib
A
- thin, flat and curved, most markedly at the cosdtal angle where the rib turns anterolaterally
- the concave internal surface has a costal groove parallelling the inferior border of the rib
18
Q
what is the purpose of the costal groove?
A
provides protecton for the intercostal nerve and vessles
19
Q
what does the head of a rib attach to?
A
the vertebral body
20
Q
what does the tubercle of a rib attach to?
A
the transverse process of the vertebra
21
Q
which ribs are ‘typical ribs’?
A
ribs 3-9
22
Q
which ribs are ‘atypical’?
A
ribs 1, 2, 11, 12
23
Q
describe rib 1
A
- not palpable
- the broadest, shortest, and most sharply curved of the true ribs
- has a single facet on its head for articualtion with T1 vertebra
- has 2 transversely directed grooves crossing its superior border
24
Q
what are the 2 grooves on the 1st rib separated by?
A
by a scalene tubercle and ridge
25
where are the grooves on the 1st rib and what are they for?
- subclavian groove — for SC artery and lowest trunk of brachial plexus)
- groove for SC vein
- subclavian groove is posterior to the scalene tubercle, groove for subclavian vein is anterior
26
what is attached to the scalene tubercle and ridge on the 1st rib?
the anterior scalene muslce
27
describe rib 2
- has a thinner, less curved body and is much larger than the 1st rib
- its head has 2 facets for articulation with T1 and T2 vertebrae
- its main atypical feature is a rough area on its upper surface = the tuberosity for serratus anterior, from whcih part of that muscle originates
28
describe ribs 10-12 and 11-12
- like 1st rib, only have 1 facet on thier heads and artiuclate with a single vertebra
- ribs 11-12 — short and have no neck or tubercle
29
what do the anterior ends of each rib consist of and what is its purpose?
costal cartialge — provides wall with mobility and elasticity
30
what is costal cartilage made up of?
hyaline cartilage
31
name 7 features of a typical vertebra
- spinous process
- lamina
- vertebral foramen
- transverse process
- body
- superior articular fact
- pedicle
32
what forms the vertebral arch?
the pedicals and the laminae form the vertebral arch around each vertebral foramen
33
what is the vertebral canal?
the tube formed by successive vertebral foramina
34
what are costovertebral joints? where do they occur? what kind of joint is formed?
- connect the rib to the bodies of the thoracic vertebrae
- the joining of the rib-vertebrae occurs at the head and tubercle of the rib
- forms a pivot joint
35
what are costotransverse joints? where are they not present?
formed by the articulation of transverse processes of thoracic vertebrae with the tubercle of their adjacent rib
- not present in T11 and T12
36
what is the sternum and what does it consist of?
= a flat, elongated bone that forms the middle of the anterior part of the thoracic cage
- consists of manubrium, body, and xiphoid process (xiphisternum)
37
what happens to the 3 parts of the sternum as you get older?
in adolescents and young adults, the 3 parts are connected together by cartilaginous joints (synchondroses) that ossify during middle to late adulthood
38
what is the xiphisternum?
a small cartilaginous process that is usually ossified in adults. fuses to body of sternum by a fibrous joint (15-29y). non-moveable joint
39
what is the sternoclavicular joint? what type of joint is it?
- formed between the clavicle and manubrium
| - a saddle type of synovial joint
40
at what level is the manubrium?
T1, rib 1
41
at what level is the sternal angle?
T4/5, rib 2 — the second rib attaches at the sternal angle — can be easily palpated so often used as a starting point as the 1st rib is not palpable
42
at what thoracic level is the body of the sternum?
T5-T9
43
at what level is the xiphoid process?
inferior end of T10
44
where are demi-facets and what do they articulate with?
on the sides of each vertebral body — they articualte with the HEADS of the ribs
45
what are costal facets? where are they present?
on transverse processes — articulate with the TUBERCLES of the ribs. only present on T1-T10
46
what facets does the manubrium contain?
- facet for articulation with costal cartilage of 1st rib
| - demi-facet for articulation with part of costal cartilage of the 2nd rib
47
what facets does the body of the sternum contain?
- articular facets for articualtion with costal cartilages of ribs 3-6
- demi-facets for articulation for parts of 2nd + 7th ribs
48
what is the definition of a facet?
cartilage lined depressions in the bone
49
what do costal facets articulate with?
ribs
50
what do articular facets articulate with?
tubercle of rib:
- smooth articular facet — articulation with corresponding transverse process of vertebra
- rough non articular facet — provides attachment for the costotransverse ligament
51
what marks the site of bifurcation of the trachea into the right and left main bronchi and corresponds with the upper boirder of the atria of the heart?
the sternal angle (angle of Louis)
52
what is the midclavicular line and what is it useful for?
- passes downwards through the middle of the clavicle
| - useful for evaluating hepatomegaly (enlarged liver), identifying heart sounds, and finding the gall bladder
53
what is the midaxillary line and what is it useful for?
- sagittal line on the torso between the anterior and posterior axillary lines
- used as a landmark for a thoracentesis (an invasive procedure to remove fluid/air from pleural space)
54
origin, insertion, innervation and action of pectoralis major
- origin: clavicle, manubrium, body of sternum, upper 6 costal cartilages
- insertion: lateral lip of bicipital groove of the humerus
- innervation: medial and lateral pectoral nerves (C5-T1)
- action: flexes, adducts and medially rotates the arm
55
origin, insertion, innervation and action of pectoralis minor
- origin: anterior ends of ribs 3-5
- insertion: coracoid process of the scapula
- innervation: medial pectoral nerve (C8-T1)
- action: stabilises scapula, draws the scapula forward, mediaward and downward
56
origin, insertion, innervation and action of serratus anterior
- origin: ribs 1-8
- insertion: medial border of scapula
- innervation: long thoracic nerve (C5-C7)
- action: protracts scapula and holds scapula against thoracic wall
57
origin, insertion, innervation and action of sternocleidomastoid
- origin: sternal head - anterior surface of the manubrium. clavicular head - medial 1/3 of clavicle
- insertion: mastoid process of temporal bone and superior nuchal line of occipital bone
- innervation: accessory nerve (CN X1), with sensory supply from C2 + C3 (for proprioception)
- flexes and laterally flexes neck. rotates neck
58
origin, insertion, innervation and action of anterior scalene
- origin: anterior tubercles of transverse processes of C3-C6 vertebrae
- insertion: scalene tubercle of 1st rib
- innervation: anterior rami of C4-C6
- action: flexes, rotates and laterally flexes neck. elevates 1st rib
59
origin, insertion, innervation and action of middle scalene
- origin: transverse processes of C2-C7 vertebrae
- insertion: superior surface of 1st rib
- innervation: anterior rami of C3-C8
- action: laterally flexes neck and elevates 1st rib
60
origin, insertion, innervation and action of posterior scalene
- origin: posterior tubercles of transverse processes of C4-C6 vertebrae
- insertion: external surface of 2nd rib
- innervation: anterior rami of C4-C6
- action: laterally flexes neck and elevates 2nd rib
61
origin, insertion, innervation and action of rectus abdominis
- origin: pubic crest and symphysis
- insertion: xiphoid process and costal cartialges of ribs 5-7
- innervation: anterior rami of T6-T12
- action: flexes trunk, compresses and provides structural support to adjacent abdominal structures
62
what are intercostal spaces and what are they covered by?
- lie between the ribs
| - covered by intercostal muscles
63
what are the intercostal muscles and how are they distinguished from each other?
- 3 layers of muscles; external, internal and innermost
| - distinguised by the direction of thier fibres
64
describe the external intercostals
- these muscles fill the intercostal space from the tubercle of the rib posteriorly to hte costochondral junction anteriorly
- fibre direction: down and inwards at front. down at outwards at back
- action = keeps the intercostal space from blowing out or sucking in during respiration
65
describe the internal intercostals
- these muscles fill the intercostal space from the angle of the rib posteriorly to the sternum anteriorly
- fibre direction: opposite to external IC muscles
- action = inspiration (only expiration when forced ie. coughing or exercise). elevates and depresses the ribs
66
describe the innermost intercostals
- lined by endothoracic fascia
- fibre direction = same as internal IC muscles but lie deep to the intercostal neurovascular bundle
- action = prevents intercostal muscles from bulging out during expiration or drawing inwards during inspiration
67
what are all the intercostal muscles innervated by?
intercostal nerves
68
origin, insertion, innervation and action of transversus thoracis muscle
- origin: posterolateral aspects of body and xiphoid process of sternum
- insertion: internal surfaces of 2nd-6th costal cartilages and costal ends of adjacent ribs
- innervation: adjacent intercostal nerves (anterior rami of thoracic nerves)
- action: depresses ribs and their costal cartilages
69
what are the boundaries of the superior thoracic aperture?
- posteriorly: vertebra T1, the body of which protrudes anteriorly into the opening
- laterally: 1st pair of ribs and their costal cartilages
- anteriorly: superior border of the manubrium
70
what are the boundaries of the inferior thoracic aperture?
- posteriorly: T12, the body of which protrudes anteriorly into the opening
- posterolaterally: 11th and 12th pairs of ribs
- anterolaterally: the joimed costal cartilages of ribs 7-10, forming the costal margins
- anteriorly: xiphisternal joint
71
role of the superior thoracic aperture
“doorway” into the thoracic cavity from the neck and upper limb — aka thoracic outlet as the important vessles and nerves which supply the head and neck exit the thorax here
72
role of the inferior thoracic aperture
provides attachment for the diaphragm — it closes the thoracic aperture, separating the thoracic and abdominal cavities almost completely
73
what is the lower edge of the rib cage formed by?
formed the cartilages of the 7th-10th ribs attaching to the sternum
74
what kind of joint is present between the head and body of thoracic vertebrae?
synovial, plane joint
75
what kind of joint is present between the tubercle and the transverse process of the thoracic vertebrae?
synovial, plane joint
76
describe the movements of the thoraic wall in expiration
= PASSIVE
- diaphragm, IC muscles and other muscles relax
- decreases intrathoracic volume
- increases intrathoracic pressure
- concurrently, intra-abdominal pressure decreases and abdominal viscera are decompressed
- causes the stretched elastic tissue of the lungs to RECOIL, expelling most of the air
77
where do the neurovascular strucutres of the thoracic wall run?
within the intercostal spaces deep to the internal intercostal muscles
78
what are the intercostal nerves formed from?
the ventral rami of T1-T11
79
what is the subcostal nerve formed from?
T12
80
where do the intercostal nerves travel?
below the posterior intercostal artery in the costal groove
81
what is each intercostal space supplied with blood by?
2 anterior intercostal arteries and 1 posterior artery (+collateral branch)
82
from what do the anterior intercostal arteries arise?
upper 6 pairs from internal thoracic (mammary) artery and the lower from musculophrenic artery
83
from what do the posterior intercostal arteries arise?
thoracic aorta (1st and 2nd from the supreme intercostal artery)
84
where do the anterior intercostal arteries pass?
one passes above and one passes below each rib
85
what do the intercostal veins drain into? exceptions?
the azygos system (apart from the upper posterior intercostal veins on the LHS which join together to form the left superior intercostal vein and empty into the left brachiocephalic vein)
86
what does the subclavian artery become and then divide into?
subclavian artery —> internal thoracic artery —> musculophrenic artery and superior epigastric artery
87
what is the diaphragm?
a musculotendinous sheet located at the inferior-most aspect of the rib cage
88
what are the 2 main functions of the diaphragm?
1. separates the thoracic cavity from the abdominal cavity
2. undergoes contraction and relaxation, altering the volume of the thoracic cavity and the lungs, producing inspiration and expiration
89
what vertebral level does the diaphragm usually lie at in expiration?
T5
90
the origin of the diaphragm consists of 3 parts; sternal, costal, and vertebral. where does each arise?
- sternal: posterior surface of xiphisternum
- costal: lower 6 ribs and their costal margins
- vertebral: right crus (from bodies L1-3), left crus (L1-L2), medial and lateral arcuate ligaments
91
where does the diaphragm insert?
central tendon
92
what nerve innervates the diaphragm?
phrenic nerve
93
does the diaphragm receive somatic or autonomic innervation?
somatic
94
what things pass through the diaphragm and at what vertebral level do they arise?
1. inferior vena cava (through central tendon) = T8
2. oesophagus (through the muscular part of the diaphragm left to the midline) = T10
3. aorta (through aortic hiatus) = T12
4. vagus nerves = with oesophagus
5. thoracic duct = behind diaphragm with aorta
6. azygos and hemiazygos veins = through aortic hiatus or crura of diaphragm
```
Caval Hiatus (T8) = IVC, terminal branches of right phrenic nerve
Oesophageal Hiatus (T10) = oesophagus, right and left vagus nerves, oesophageal branches of left gastric artery/vein
Aortic Hiatus (T12) = aorta, thoracic ducy, azygos vein
```
95
in expiration why does the right dome of the diaphragm lie higher than the left?
because the liver is situtated under the right dome
96
what are the 2 serous membranes of the pleura and what do they cover?
1. visceral — covers lungs
| 2. parietal — covers internal surface of the thoracic cavity (lines endothoracic fascia)
97
where are the 2 pleural membranes continuous with each other?
at the hilum of the lung
98
which pleura is thicker?
parietal pleura
99
what is the parietal pleura divided into?
1. costal pleura = lines inner aspect of rib cage
2. diaphragmatic pleura = covers the superior surface of the diaphragm
3. mediastinal pleura = located in the mediastinum
4. cervical plura = projects into the neck
100
what is the pleural cavity?
= a potential space
| = a slit-like space between the 2 pleural membranes that is lined by a thin film of pleural fluid
101
what holds the 2 membranes together and what does this mean?
surface tension holds them together, meaning the outer surface of the lung is in contact with the thoracic wall
102
what happens if air enters the pleural cavity from the lung or chest wall?
the lung collapses — the pressure against the lung causes it to collapse — prevents the lung from expanding properly when you try breathe in, causing a shortness of breath and chest pain — = pneumothorax
103
what are the pleural recesses?
- costodiaphragmatic = between costal and diaphragmatic paritetal pleura along the inferior border
- costophrenic = between the costal and mediastinal parietal pleura along the anterior norder
104
what type of innervation do the intercostal muscles provide?
somatic
105
what structures are supplied by the intercostal nerves?
intercostal muscles, parietal pleura and overlying skin
