Anatomy 1 - Thorax: Cage, Wall, Boundaries, Surface Anatomy Flashcards
(40 cards)
1
Q
Thorax
A
- skeletal cage + wall
- skin, subcutaneous tissue, muscle, fascia
- wall is rigid, not very thick
- horizontal ribs connected by cartilage
- supported by vertical sternum and thoracic verterbrae
- protect vital thoracic and abdominal organs
2
Q
Bones in thoracic cage
A
- 1 sternum
- 12 thoracic vertebrae
- 11 intervertebral discs
- 12 pairs of ribs
- 12 pairs of associated costal cartilagenous
3
Q
Manubrium
A
- widest, thickest part of sternum
- located TV3 - TV5
- Joins body of sternum creating the manubriosternal joint - forms sternal angle
- 1 Jugular notch, 2 clavicular notch, 2 synchondroses of 1st rib, 2 hald costal notch for 2nd rib
4
Q
Body of sternum
A
- longest, thinnest part of sternum
- located TV5-TV9
- creates manubriosternal joint with manubrium
- forms xiphisternal joint with xiphoid process
- 2 half costal notch for 2nd ribs, 2 x full costal notches for 3rd, 4th, 5th and 6th ribs
- 2 half costal notch for 7th rib
5
Q
Xiphoid process : sternum
A
- smallest part of sternum
- TV9-10
- Participates in xiphisternal joint
- 2 half costal notch for 7th rib
6
Q
Xiphisternal joint is a marker for
A
- inferior limit of thoracic cavity
- inferior border of hear
- superior limit of liver
- central tendon of diaphragm
7
Q
Variations in TV1
A
- superior costal facet on vertebral body is not a demi-facet but a single costal facet for 1st rib articulation
- inferior costal facet is a demi-facet for hald of the head of the 2nd rib
8
Q
Variations in TV10
A
- only has a single costal facet (no superior and inferior), positioned in between the vertebral body and pedicle
9
Q
Variations in TV11-12
A
- only a single costal facet positioned on the pedicle, for 11th and 12th rib articulation and no costal facet on the transverse process
10
Q
Atypical ribs: 1 2 10 11 12
A
Rib 1 - no crest or angle; wide flat and groovy
Rib 2 - long neck, wide and rough
Rib 10 - no crest
Rib 11: no crest, neck or tubercle
Rib 12 - no crest, neck, tubercle, angle or costal groove
11
Q
Surface features of 1st and 2nd ribs
A
1st rib
- subclavian vein groove
- subclavian artery groove
- scalene tubercule
2nd rib features
- serratur anterior tuberosity
12
Q
Costal cartilage attachments
A
- “true” Ribs 1-7: attach directly to sternum
- “False” Ribs: 8-10: attach to sternul via cartilage of rib above
- “floating” ribs 11-12: costal cartilage form only caps on the ribs tips and do not attach to sternum
13
Q
Costochondral joints
A
Between anterior rib and costal cartilage
14
Q
Sternocostal joints
A
Between sternum and costal cartilage of rib
15
Q
Costovertebral joint
A
- between posterior rib and thoracic vertebrae
- costocorporeal: between rib head and vertebral body
- Costotransverse: between rib tubercle and transverse process
16
Q
What types of joints are the following?
- Manubriosternal
- Xiphisternal
- Sternocostal
- Interchondral
- Costochondral
- Costocorporeal
- Costotransverse
- Zygapophysial
A
- Manubriosternal:2º cartilaginous
- Xiphisternal: 1º Cartilaginous
- Sternocostal: 1st Cartilaginous, 2-7 Synovial
- Interchondral: 6-8 Synovial, 9-10 fibrous
- Costochondral: 1º Cartilaginous
- Costocorporeal: Synovial
- Costotransverse: Synovial
- Z joint: synovial
17
Q
Superficial to deep thoracic wall muscle
A
- External intercostal muscles
- Internal intercostal muscles
- innermost intercostal muscles
- Subcostal muscles
- Transversus thoracic muscle
18
Q
External intercostal muscle
A
- Direction: hand into same side pocket
- Function: move ribs up
- involved in inspiration
19
Q
Internal intercostal muslces
A
- Hand into opposite side pocket
- move ribs down
- involved in expiration
20
Q
Innermost intercostal muscle
A
- hand into opposite side pocket
- move ribs down
- involved in expiration
21
Q
Subcostales muscle
A
- innermost layer on posterior wall
- anterior aspect of posterior thoracic wall
- span a couple of intercostal spaces
- depress ribs during expiration
22
Q
Transversus thoracic muscle
A
- posterior aspect of anterior wall
- pulls sternum back during expiration
23
Q
Where is the neurovascular bundle located
A
- in between internal intercostal membrane and innermost intercostal muscle
24
Q
Thoracic wall vessels and nerved
A
- Intercostal veins, arteries and nerves run in costal grooves on the inferior borders of ribs
- Vein superior, Artery middle, Nerve inferior
- then give off smaller collateral branches near the rib angle which run along the superior border of the rib below: collateral nerve superior, collateral artery middle and collateral vein inferior
25
Thoracic wall veins
- posterior intercostal veins drawin to azygous (right) /hemiazygous (left) system which ends up in SVC. Also drains to superior intercostal vein and brachiocephalic vein
- Anterior intercostal vein dreins to internal thoracic vein then to brachiocephalic vein
- Subcostal veins drain to azygous/hemiazygous system
26
Thoracic wall arteries
- Posterior intercostal arteries from thoracic aorta and superior intercostal artery (which itself coems from sublavian artery)
- anterior intercostal artery comes from internal thoracic artery which itself comes from subclavian artery
- Subcostal arteries come from thoracic aorta
27
Thoracic wall nerves
- intercostal nerves from anterior rami if T1-11 spinal nerves.
- separate into lateral cutaneous branch at rib angle and anterior cutaneous branch at sternum
- subcostal nerves come from anterio rami T12 spinal nerves
28
Thoracic wall lymphatics
- Upper to bronchomediastinal trunk which then goes to junction of internal jugular and subclavian bein
- lower to thoracic duct and then to junction of left internal jugular and subclavian vein
- Parasternal lyhmph nodes go to bronchomediastinal trunk and then to junction of internal jugular and subclavian veins
29
Thorax boundaries
- Thoracic inlet: superior border of manubrium, 1st pair of ribs and costal cartilge, TV1.
- Thoracic outlet: Xiphisternal joint, costal cartilages of 7-10 pairs of ribs and ends of 11-12 pairs of ribs (lateral), TV12, closed off from abdomen: diaphragm
30
Thoracic inlet contents (anterior to posterior)
- brachiocephalic veins
- subclavian veins
- internal jugular veins
- vagus nerves
- Thoracic duct
- Internal carotid arteries
- Phrenic nerves
- subclavian arteries
- Trachea
- Recurrent laryngeal nerves
- Apex of lungs
- Oesophagus
- T1 intercostal nerves
- Anterior rami of T1 spinal nerves
31
Thoracic outlet contents
- filled with thin, double domed, musculotendinous sheet that separates thorax and abdomen and attaches to inferior margin of thoracic cage and superior lumbar vertebrae: diaphragm
32
Diaphragm structure
- at expiration, right dome is at 5th rib level, left dome is at 5th intercostal space
- IVC punctures central tendon at TV8
- Oesophagus passes through muscular part posterior to central tendon at TV10
- aorta passes behind the posterior attachment at TV12
33
Diaphragm attachments
- xiphoid process of sternum
- cartilaginous costal margin of thoracic wall (7-10th rib)
- Ends of 11-12th rib
34
Ligaments that span across structures of posterior abdominal wall
- over quadratus lumborum: Lateral arcuate ligaments
- Over psoas major: Medial arcuate ligament
- Over aorta: Median arcuate ligament
35
Musculotendinous bands on lumbar vertebrae
- right crus attach to LV1-3
| - Left crus attach to LV1-2
36
Diaphragm arterial supply
- Superior surface by superior phrenic artery (from thoracic aorta), musculophrenic artery and pericardiophrenic artery (from internal thoracic artery)
- Inferior surface by inferior phrenic artery (from abdominal aorta)
37
Venous drainage of diaphragm
- generally parallel arteries
| - drain to azygous system, brachiocephalic vein and inferior vena cava
38
Diaphragm lymphatics
- lymphatic plexuses on superior and inferior surfaces of diaphragm communicate freely with each other
- anterior and posterior diaphragmatic lymph nodes -> to parasternal nodes -> to bronchomediastinal trunk and junction of internal jugular and subclavian veins
39
Diaphragm innervation
- phrenic nerve
- arises bilaterally from anterior ramin of 3rd, 4th and 5th cervical spinal nerves
- run along the lateral aspects of the pericardium and pierce diaphragm to innervate it on the inferior surface
- each innervates its relative half of the diaphragm
- provide entire motor supply for contraction of diaphragm
- also provides sensory innervation to diaphragm, pericardium and pleura
40
Sternal angle important landmark
- superior and inferior mediastinum separate
- aortic arch starts and finishes
- pulmonary trunk bifurcates
- trachea bifurcates
- ligamentum aretiosum is prsent
- axygos vein enters SVC
- thoracic duct moves from right to left
- recurrent laryngeal nerve loops under aortic arch
