Chest Wall

Question 1

Thoracic inlet boundaries

Answer 1

It is defined by the upper border of the first pair of ribs, the upper border of the manubrium of the sternum and the anterior border of vertebral body T1.

Question 2

Thoracic outlet boundaries

Answer 2

it is closed by the diaphragm, which separates the thoracic cavity from the abdominal cavity, xiphoid process and rib 12

Question 3

Structures that pass through the thorax

Answer 3

Oesophagus, trachea, arteries, veins, lymphatics and nerves

Question 4

External intercostal muscles (anatomy and function)

Answer 4

most superficial intercostal muscles
originate from the inferior border of one rib, course inferomedially and insert to the superior border of the immediate rib below

function of the external intercostal muscles is to elevate the ribs during forced inspiration

Question 5

Internal intercostal muscles (anatomy and function)

Answer 5

form the middle layer of the intercostal musculature
originate from the costal groove of one rib, course superomedially and insert to the superior border of the immediate rib below

function of the internal intercostal muscles is to depress the ribs during forced expiration.

Question 6

Innermost intercostal muscles (anatomy and function)

Answer 6

the deepest intercostal muscles
originate from the costal groove of one rib, posteriorly to the origin of the internal intercostals. They course superomedially, in the same fashion as the internal intercostals, and insert to the superior border of the immediate rib below

function of the innermost intercostals is to assist in the depression of ribs during forced expiration

Question 7

inspiration

Answer 7

diaphragm muscles contract and flatten, external intercostal muscles contract elevating the ribs and sternum increasing thoracic volume, active

Question 8

expiration

Answer 8

diaphragm muscles relax and dome, external intercostal muscles relax to depress the ribs and sternum decreasing thoracic volume, passive

Question 9

forced expiration

Answer 9

the abdominal muscles contract and force the diaphragm upwards and contraction of the internal intercostal muscles actively pulls the ribs downwards

Question 10

Bony thorax is formed by…

Answer 10

formed by the sternum, 12 thoracic vertebrae and 12 pairs of ribs.

Question 11

Costo and chondro meaning

Answer 11

Costo = rib
Chondro = Cartilage

Question 12

Typical vs atypical ribs

Answer 12

Atypical- 1,2,10,11 and 12 have unusual features eg. Rib 1 is flat and has distinct tubercles, rib 10 only has 1 articulatory facet on its head

Question 13

Costotransverse and costovertebral joints are…

Answer 13

synovial

Question 14

Rib movement in inspiration and expiration

Answer 14

Question 15

Quiet respiration uses…

Answer 15

Question 16

Forced respiration uses…

Answer 16

Question 17

Muscles of respiration

Answer 17

Question 18

Chest drains are inserted…

Answer 18

Inserted above the rib to avoid damage to the neurovascular bundle. Usually placed between the anterior axillary and the mid axillary line in the 4th or 5th intercostal space.

Question 19

Intercostal muscles arterial supply

Answer 19

Posterior intercostal arteries:
1+2: Supreme intercostal artery 3-11: Thoracic aorta

Anterior intercostal arteries: Internal thoracic artery
1-6: Direct branches
7-11: Musculophrenic artery

Question 20

Intercostal muscles venous drainage

Answer 20

Parallels arterial supply- intercostal veins. They drain into the Azygous vein (most posterior veins) and internal thoracic veins (anterior).

Question 21

Intercostal muscles innervation

Answer 21

Intercostal nerves T1-T11
Subcostal nerve T12

Question 22

Anatomy of the diaphragm- where it attaches

Answer 22

Question 23

Functional anatomy of the diaphragm

Answer 23

Respiratory and non-respiratory

Question 24

What are the 3 diaphragmatic openings?

Answer 24

Caval opening T8
Oesophageal hiatus T10
Aortic hiatus T12

Question 25

Diaphragm innervation

Answer 25

The phrenic nerves - C3, C4, C5 (all motor).

Question 26

What is the order of the structures of the intercostal neurovascular bundle from superior to inferior? What feature of the rib is this most associated with?

Answer 26

Vein
Artery
Nerves

Costal groove