Brachial Plexus

Question 1

What is the brachial plexus?

Answer 1

A network of nerves supplying the skin and muscles of the upper limb. Originates from C5-T1 and passes through the Axilla.

Question 2

Can you label the spinal nerve roots, trunks, divisions (anterior and posterior) and cords of the brachial plexus?

Answer 2

Question 3

Label all the minor cords of the brachial plexus

Answer 3

Question 4

Describe the origins of the nerves of the Brachial Plexus

Answer 4

Musculocutaneous Nerve: C5,6,7

Axillary Nerve: C5,6

Median Nerve: C5-T1 (NB variations in different text books)

Radial Nerve: C5-T1

Ulnar Nerve: C8,T1 (again some texts have variations)

Question 5

Describe an Upper Brachial Plexus Injury

Answer 5

Erb’s Palsy: Damage to roots C5 and 6 from excessive increase in the angle between the neck and the shoulder

Affects nerves derived primarily from C5 and 6

• Weakens muscles responsible for a series of actions producing the “waiters tip” deformity

Question 6

Describe a Lower Brachial Plexus Injury

Answer 6

Klumpke’s Palsy

Much less common injury

Occurs from excessive abduction of the arm

Affects nerves derived from the T1 root (the mainly ulnar and median nerves)

Paralyses the small muscles of the hand

And sensory loss along the medial side of the arm