Anatomy Dissection 9 - Axilla and Brachial Plexus

Question 1

Name of the pyramidal space inferior to the shoulder joint and just superior to what patient’s refer to as the “armpit”?

Answer 1

Axilla

Question 2

What forms the medial wall of the axilla?

Answer 2

Superolateral aspect of the chest

Question 3

What forms the anterior wall of the axilla?

Answer 3

Pectoralis major (lower border is contained in the inferior edge of the anterior axillary fold)

Question 4

Give 2 purposes of pectoralis major?

Answer 4

One of the main muscles of climbing (along with latissimus dorsi)
Important accessory muscle of inspiration

Question 5

What is the axillary vein a continuation of?

Answer 5

Brachial vein

Question 6

When does the brachial vein become the axillary vein?

Answer 6

At the lower border of teres major

Question 7

What marks the inferior extent of the axilla?

Answer 7

Teres major

Question 8

What aspect of the axilla does teres major contribute to?

Answer 8

posterior wall

Question 9

When does the subclavian artery become the axillary artery?

Answer 9

at the lateral border of the first rib

Question 10

What spinal nerves form the brachial plexus?

Answer 10

anterior rami of spinal nerves C5 - T1

Question 11

Draw the brachial plexus

Answer 11

…

Question 12

What spinal nerves forms the superior trunk of the brachial plexus?

Answer 12

C5 and C6 anterior rami

Question 13

what spinal nerves form the middle trunk of the brachial plexus?

Answer 13

C7 anterior rami

Question 14

What spinal nerves forms the inferior trunk of the brachial plexus?

Answer 14

C8 and T1 anterior rami

Question 15

What divisions/ trunks gives the medial cord of the brachial plexus?

Answer 15

Direct continuation of the anterior division of the lower trunk

Question 16

Which divisions/ trunks gives the lateral cord of the brachial plexus?

Answer 16

Anterior divisions of the superior and middle trunks

Question 17

Which divisions/ trunks gives the posterior cord of the brachial plexus?

Answer 17

Posterior divisions of all 3 trunks

Question 18

What cords form the ulnar nerve?

Answer 18

Direct continuation of the medial cord

Question 19

What cords form the musculocutaneous nerve?

Answer 19

Direct continuation of the lateral cord

Question 20

What does the posterior cord of the brachial cord divide to give?

Answer 20

Axillary and radial nerves

Question 21

What cords is the median nerve formed from?

Answer 21

Medial and lateral cord

Question 22

What do the roots and trunks of the brachial plexus lie between?

Answer 22

Anterior and middle scalene muscles in the root of the neck

Question 23

Where in the neck are the divisions of the brachial plexus located?

Answer 23

Immediately posterior to the subclavian vessels in the root of the neck (deep to the clavicle)

Question 24

Where in the body do the cords of the brachial plexus lie?

Answer 24

Around the axillary artery (which is distal to the first rib)

Question 25

What does the musculocutaneous nerve supply?

Answer 25

The muscles of the anterior compartment of the arm

Question 26

Which compartment of the arm does the axillary and radial nerve pass into?

Answer 26

Posterior compartment

Question 27

Where does the axillary nerve lie in relation to the radial nerve?

Answer 27

Superior

Question 28

What structure does the axillary nerve wrap around?

What is it susceptible to here?

Answer 28

The posterior aspect of the surgical neck of the humerus

Injury in shoulder dislocation or fracture of the neck of the humerus

Question 29

What structure does the radial nerve wrap around?

What is it susceptible to here?

Answer 29

Posterior aspect of the mid-shaft of the humerus

Injury by mid-shaft humeral fractures

Question 30

What is the most medial of the named nerves of the brachial plexus?

Answer 30

Ulnar nerve

Question 31

Where does the ulnar nerve pass from the brachial plexus?

Answer 31

posteriorly into the medial aspect of the arm

Question 32

What forms the middle of the M-shaped configuration of the named nerves of the brachial plexus/

Answer 32

Median nerve

Question 33

What are the 3 main groups of axillary lymphatics

?

Answer 33

Apical
Central
Basal

Question 34

What do the apical lymph nodes drain towards?

Answer 34

Right lymphatic/ thoracic duct

Question 35

What do the central lymph nodes drain towards?

Answer 35

Apical lymph nodes

Question 36

What do the basal lymph nodes drain towards?

Answer 36

Central lymph nodes

Question 37

What are the 3 groups of lymph nodes that make up the basal axillary lymph nodes/

Answer 37

Pectoral
Subscapular
Humeral

Question 38

Name of the lymph nodes located along the lateral border of pectoralis minor?
What does these lymph nodes receive a lot of lymph from?

Answer 38

Pectoral

Breast

Question 39

What are the name of the lymph nodes that receive lymph from the scapular region?

Answer 39

Subscapular lymph nodes

Question 40

What are the lymph nodes which receive such of the upper limb lymphatics?

Answer 40

Humeral lymph nodes