Axilla and Brachial Plexus

Question 1

What muscles are covered by clavipectoral fascia?

Answer 1

Subclavius

Pectoralis Major

Question 2

What 3 structures pierce the clavipectoral fascia?

Answer 2

Cephalic vein
Thoracoacromial artery
Lateral pectoral nerve

Question 3

What forms the boundaries of the axilla?

Answer 3

Anterior - pec major and minor, subclavius, fascia
Floor - skin and into arm
Roof - Rib 1, clavicle, scapula
Posterior wall - subscapularis, teres major, latissimus dorsi, long head of triceps brachii
Lateral wall - humerus
Medial - serratus anterior and wall of thorax

Question 4

What is contained within the axilla?

Answer 4

• Vessels, nerves and lymphatics of the upper limb
• Short head of bicpes and coracobrachiallis
• Lymph nodes that drain both the upper limb and mammary tissue
• Adipose tissue

Question 5

What does the basilic vein drain?

Answer 5

Drains the posterio-medial surface of the hand and forearm, then at the lower margin of the teres major it becomes the axillary vein

Question 6

What vein gives rise to the axillary vein?

Answer 6

Brachial vein

Question 7

At which structure does the axillary vein become the subclavian vein?

Answer 7

Anterior to axillary artery in axilla at lateral border of rib 1

Question 8

What veins join to the axillary vein?

Answer 8

Brachial veins and cephalic vein

medial brachial vein may join basilic vein

Question 9

What lies inferior to the axillary vein?

Answer 9

The axillary artery

Question 10

What gives off the axillary artery and what does it become?

Answer 10

Subclavian becomes axillary as it crosses the lateral border of the 1st rib

Axillary becomes brachial artery once it leaves the axilla and passes through the axilla and passes over inferior border of teres major

Question 11

What are the 3 parts of the axillary artery?

Answer 11

1st - 1 branch. Superior thoracic artery. Lies proximal to pec minor

2nd - 2 branches. Thoracromial and lateral thoracic arteries. Lies posterior to pec minor

3rd - 3 branches. Subscapular and ant and post circumflex humeral arteries. Distal to pec minor

Question 12

What regions of the body drain into the axillary lymph nodes?

Answer 12

Upper limb, lateral breast tissues, upper back, shoulder and lower neck

Question 13

What are the 5 axillary node groups?

Answer 13

Humeral - posterior to axillary vein. Drains upper limb

Pectoral - inferior margin of pec minor. Thorax and mammary

Subscapular - posterior axillary wall. Back shoulder and neck.

Central - axillary fat. Communicate with the other nodes.

Apical - Superior margin of pec minor. Drains other nodes and mammary tissue

Question 14

Where does lymph from the medial region of the breast drain?

Answer 14

Internal thoracic nodes

Question 15

What rami make up the brachial plexus?

Answer 15

Anterior rami C5-T1

Question 16

What are the regions of the brachial plexus from proximal to distal?

Answer 16

Roots, Trunks, Divisions, Cords, Branches

Real, Texans, Drink, Cold, Beer

Question 17

What roots form the 3 trunks of the brachial plexus?

Answer 17

Superior trunk - C5 and C6
Middle trunk - C7
Inferior trunk - C8 and T1

Question 18

What are some of the nerves that originate from the roots of the brachial plexus?

Answer 18

C5 root to the phrenic nerve (diaphragm) and dorsal scapular nerve (rhomboid major and minor)

C5-7 roots to the long thoracic nerve (serratus anterior)

Question 19

What trunk gives rise to other nerves before continuing on as the brachial plexus?

Answer 19

Superior trunk

C5,6 to suprascapular nerve (infraspinatous and supraspinatous) and nerve to subclavius (subclavian)

Question 20

What are the divisions of each trunk?

Answer 20

Each trunk divides into an anterior and posterior division

Question 21

What part of the upper limb do the anterior divisions of the trunks supply?

Answer 21

Anterior compartments of the arm and forearm

Forms - musculocutaneous, median and ulnar nerves

Question 22

What part of the upper limb are the posterior divisions associated with?

Answer 22

Posterior compartments of arm and forearm

Forms Radial nerve

Question 23

What are the cords of the brachial plexus?

Answer 23

Lateral, Medial and Posterior

Named relative to their position to the axillary artery

Question 24

What forms the lateral cord of the brachial plexus?

Answer 24

Unites anterior divisions of upper and middle trunks therefore C5-7 fibres present

Origin of lateral pectoral nerve

Question 25

What forms the posterior cord of the brachial plexus?

Answer 25

Unites all posterior divisions of the trunks therefore has C5-T1 fibres

Origins of subscapular and thoracodorsal nerves

Question 26

What forms the medial cord of the the brachial plexus?

Answer 26

Continuation of anterior division of the inferior trunk therefore C8-T1 fibres

Origins of medial pectoral and cutaneous nerves

Question 27

What are the terminal branches of the brachial plexus?

Answer 27

Musculocutaneous
Median
Axillary 
Radial 
Ulnar

Question 28

What cords give what terminal nerves?

Answer 28

Lateral cord- musculocutaneous nerve, lateral root of the median nerve

Posterior cord- axillary and radial nerve

Medial cord - ulnar and medial root of the median nerve