Brachial plexus

Question 1

What does the brachial plexus supply?

Answer 1

The upper limb

Question 2

Which spinal nerve roots are involved?

Answer 2

anterior rami of C5, C6, C7, C8, T1

Question 3

Really tired drink coffee now

Answer 3

Roots 
Trunks 
Divisions 
Cords 
Nerves

Question 4

Trunks: Superior, middle and inferior

Answer 4

Superior: C5 + C6
Middle: C7
Inferior: C8 + T1

Question 5

Divisions

Answer 5

Anterior and posterior

Question 6

Cords

Answer 6

Named according to their relationship to the axillary artery
Outer = lateral
Middle = posterior
Inner = medial

Question 7

Which nerves make up the M shape?

Answer 7

Musculucutaneous nerve - lateral
Median nerve - from branches of lateral and medial cords
Ulnar nerve - Continues from medial cord

Question 8

Which nerves does the posterior cord give rise to?

Answer 8

Axillary nerve

Radial nerve

Question 9

Which nerves does the lateral for give rise to?

Answer 9

Musculocutaneous nerve

Median nerve

Question 10

Which nerves does the medial cord give rise to?

Answer 10

Ulnar nerve

Median nerve

Question 11

Where are roots and trunks located?

Answer 11

Between anterior and middle scalene muscles in the root of the neck

Question 12

Where are divisions located?

Answer 12

Posterior to the subclavian vessels in the root of the neck

Question 13

Where are cords located?

Answer 13

They lie around the axillary artery

Question 14

Musculocutaneous nerve - route

Answer 14

Pierces through the coracobrachialis muscle

Question 15

Musculocutaneous nerve - what does it supply?

Answer 15

Muscles of the anterior compartment of the arm

• Coracobrachialis
• Biceps brachii
• Brachialis

Question 16

Median nerve - route

Answer 16

Comes down the medial aspect of the arm then crosses anteriorly at the elbow (cubital fossa) and enters the forearm, then passes through the wrist and into the hand

Question 17

Median nerve - what does it supply?

Answer 17

Motor nerve fibres supply the majority of the anterior forearm muscles and the thenar eminence muscles
Somatic nerve fibres supply the LATERAL 3 and a half fingers of the palmar aspect of the hand and the skin over the nailbed of thumb, index, middle finger and lateral half of ring finger

Question 18

Ulnar nerve - route

Answer 18

Passes from the anterior compartment of the arm posterior to the medial epicondyle (via cubital tunnel and flexor carpi ulnaris) to the anterior compartment of the forearm. It then passes into the hand

Question 19

Ulnar nerve - what does it supply?

Answer 19

Motor nerve fibres supply the majority of muscles in the hand (apart from thenar eminence), also supplies some of the muscles of the anterior forearm
Somatic nerve fibres supply the medial 1 and a half fingers

Question 20

Axillary nerve - route

Answer 20

Enters the posterior compartment of the arm.
Wraps around the posterior aspect of the surgical neck of the humerus
Located in the quadrangular space.
Lies superior to the radial nerve

Question 21

Axillary nerve - what does it supply?

Answer 21

Deltoid muscle and teres minor muscle

Sensory nerve fibres supply the badge patch area (over the lateral aspect of the arm)

Question 22

Radial nerve - route

Answer 22

From the radial groove of the humerus to the lateral aspect of the cubital fossa

Question 23

Radial nerve - what does it supply?

Answer 23

Motor nerve fibres supply the posterior compartment of the arm (triceps) and forearm
Sensory nerve fibres supply the skin over the lateral aspect of the dorsum of the hand
RADIAL NERVE ALWAYS STAYS POSTERIOR

Question 24

What is the deep branch of the radial nerve called? and what does it supply?

Answer 24

Posterior interosseous nerve

Supplies the posterior compartment of the forearm

Question 25

In a shoulder dislocation or fractured surgical neck of the humerus, which nerve is vulnerable to injury?

Answer 25

Axillary nerve

Question 26

How do you test for axillary nerve damage?

Answer 26

Get patient to close eyes, feel badge patch area.

If patient feels you do the then it is likely that their axillary nerve is in tact

Question 27

In a mid-shaft humeral fracture, which nerve is vulnerable to damage?

Answer 27

Radial nerve

Question 28

Damage to radial nerve causes which clinical finding?

Answer 28

Wrist drop