Thoracic Wall

Question 1

Boundaries of thoracic wall

Answer 1

-superior thoracic aperture: vertebra T1, rib 1 and manubrium
-inferior thoracic aperture: vertebra T12, rib 12, end of rib 11, costal margin and xiphoid process

Question 2

Which ribs are typical? Atypical?

Answer 2

Typical = 3-9
Atypical = 1, 2, 10-12

Question 4

Distinct features of atypical ribs

Answer 4

1: shortest, curved grooves for subclavian vessels, only one articular facet in the head

2: flat and tuberosity for the SA

10-12: only 1 articular facet on the head

11-12: no tubercles and no articulation with sternum

Question 5

Why is the sternal angle a clinical landmark?

Answer 5

-at level of T4-T5 intervertebral disc
-overlies the aortic arch on L and SVC on R
-roughly level at bifurcation of trachea and pulmonary trunk

Question 6

Where are intercostal spaces? What do they contain, where are they found?

Answer 6

-found between adjacent ribs
-intercostal vein, artery and nerve (found in costal groove)

Question 7

External intercostal OIIA

Answer 7

O: inferior margin of rib above

I: superior margin of rib below

I: intercostal nerves

A: most active during inspiration; supports intercostal space and moves ribs superiorly

Question 8

Internal intercostal OIIA

Answer 8

O: lateral edge of costal groove of rib above

I: superior margin of rib below

I: intercostal nerves

A: most active during expiration; supports intercostal space; moves ribs inferiorly

Question 9

Innermost intercostal OIIA

Answer 9

O: medial edge of costal groove of rib above

I: internal aspect of superior margin of rib below

I: intercostal nerves

A: acts with internal intercostal muscles

Question 10

Subcostal OIIA

Answer 10

O: internal surface (near angle) of lower ribs

I: internal surface of second or third rib below

I: related intercostal nerves

A: depress ribs

Question 11

Trasversus thoracis OIIA

Answer 11

O: inferior margins and internal surfaces of costal cartilages of second to sixth ribs

I: inferior aspect of deep surface of body sternum, xiphoid process, and costal cartilages ribs 4-7

I: related intercostal nerves

A: depresses costal cartilages

Question 12

What are the four main arteries in the thoracic wall?

Answer 12

Anterior intercostal, posterior intercostal, internal thoracic, musculophrenic

Question 13

What are the 6 main veins of the thoracic wall?

Answer 13

R superior intercostal, L superior intercostal, azygos, accessory hemiazygos, internal thoracic, hemiazygos

Question 14

What are intercostal nerves? Where do they come from?

Answer 14

Nerves found in between ribs; anterior rami of spinal nerves T1-T11

Question 15

What innervates the abdominal wall?

Answer 15

Anterior ramus of spinal nerve T12, inferior to rib 12