General course

Question 1

What are the subdivisions of the brachial plexus?

Answer 1

Roots, Trunks, Divisions, Cords, Branches

Question 2

What are the trunks called?

Answer 2

Superior (C5,C6), Middle (C7), Inferior (C8,T1)

Question 3

What are the roots of the brachial plexus?

Answer 3

C5-T1

Question 4

How many divisions are there?

Answer 4

6

Question 5

What are the cords called? What are they named in relation to?

Answer 5

Lateral, Posterior, Medial

Second part of the axillary artery

Question 6

Describe the course of the brachial plexus, up to the branches

Answer 6

Brachial plexus begins as the anterior rami of C5-T1
Emerge from the intervertebral foramen of their respective vertebrae
Lie in the posterior triangle of the neck
Trunks pass laterally between the anterior and medial scalene muscles and cross the base of the posterior triangle of the neck
Found behind the subclavian artery, pass over apex of the lung and the first rib towards the clavicle
Go behind the middle third of the clavicle where each trunk splits into divisions
Pass behind the clavicle to enter the axilla
Cords travel laterally with the axillary artery towards the arm (ensheathed by the axillary sheath)
Cords divide around the third part of the axillary artery into five terminal branches