Thoracic Wall

Question 1

Describe the location of the intercostal veins, arteries, nerves

Answer 1

Between the internal intercostal muscle and the innermost (intimal) intercostal muscle

Question 2

What anatomic structure marks the internal limit of the thoracic wall

Answer 2

Endothoracic Fascia

• thin fibrous layer of connective tissue that is continuous with the most internal component of the investing fascia of the intercostal muscles
• the parietal pleura rests on the endothoracic fascia

Question 3

Name the intercostal muscles

Answer 3

11 pairs each, from superficial to deep:

• External intercostals (down / forward)
• Internal intercostal muscle (down / posterior)
  * *intercostal artery, vein, neves**
• Innermost intercostal muscles - intercostales intimi - (more vertical fibers)
  * * endothoracic fascia**

Question 4

Layers of thorax at breast, from superficial to deep

Answer 4

Epidermis
Dermis
Sub q fat
**Anterior branch of intercostal nerve seen in sub q near lateral edge of sternum*
** Lateral branch of intercostal nerve and artery seen in sub q near lateral edge of breast**
Mammary gland, within superficial fascia
Pectoralis major
Pectoralis minor
Serratus
External intercostal
Internal intercostal
**Intercostal artery, vein, nerve*
Innermost intercostal muscle
**Endothoracic fascia*
Parietal pleura

Question 5

Origins of the intercostal nerves

Answer 5

Intercostal nerves are direct continuations of the ventral primary rami of the upper 11 thoracic spinal nerves

Question 6

posterior intercostal arteries (spaces 3-11) arise from

Answer 6

thoracic aorta

Question 7

First two spaces of posterior intercostal arteries arise from

Answer 7

superior intercostal arteries, which come from the costocervical trunk

Question 8

anterior intercostal arteries of upper 5 spaces arise from

Answer 8

internal thoracic (internal mammary) artery

Question 9

anterior intercostal arteries of lower 6 spaces

Answer 9

musculophrenic artery

Question 10

posterior intercostal VEINS drain into

Answer 10

azygos and hemiazygos systems

Question 11

anterior intercostal VEINS drain into

Answer 11

musculophrenic and internal thoracic veins

Question 12

superficial muscles of the pectoral region

Answer 12

pectoralis major
pectoralis minor
subclavius

Question 13

two origins / divisions and insertion of pectoralis major

Answer 13

Origins: clavicle and sternum at 2nd-6th ribs

Insertion: crest of greater tubercle of humerus

Question 14

anatomic landmark that defines the separation of the upper lateral border of the pectoralis major from the deltoid muscle

Answer 14

CEPHALIC VEIN

Question 15

General action of pectoralis major

Answer 15

Brings arm across the chest

Question 16

Origins and insertion of pectoralis minor

Answer 16

Origin: 2nd-5th ribs

Insertion: coracoid process of scapula

Question 17

General action of pectoralis minor

Answer 17

Lower the shoulder

Accessory muscle of respiration

Question 18

Origins and insertion of subclavius muscle

Answer 18

Origin: 1st rib

Insertion: inferior surface of clavicle