Brachial Plexus

Question 1

Which nerve roots derive the BP?

Answer 1

C5-T1

Question 2

Which nerve roots are damaged in an upper BP injury?

Answer 2

C5/6

Question 3

Which nerves are damaged in an upper BP injury?

Answer 3

Axillary, musculocutaneous and supracscapular Nn

Question 4

Where does the BP protrude through the musculature?

Answer 4

Between the anterior and middle scalene mm - with the subclavian a.

Question 5

What are the names of the trunks of the BP?

Answer 5

Superior, Middle and Inferior

Question 6

What are the terminal branches of the BP?

Answer 6

Axillary, Musculocutaneous, Median, Ulnar and Radial Nn

Question 7

From which roots does the Axillary N arise?

Answer 7

C5/6

Question 8

From which trunk does the Axillary N arise?

Answer 8

Posterior

Question 9

Which nerve is most at risk at the neck of the humerus?

Answer 9

Axillary

Question 10

Name two muscles supplied by the Axillary N

Answer 10

Deltoid and Teres Min

Question 11

What is the sensory distribution of the Axillary N?

Answer 11

The shoulder patch

Question 12

What would the impact be of Axillary N damage?

Answer 12

Inability to abduct arm - loss of sensation over the shoulder

Question 13

From which roots does the Musculocutaneous N arise?

Answer 13

C5-7

Question 14

The Musculocutaneous N is an extension of which cord of the BP?

Answer 14

Lateral Cord

Question 15

Name three muscles innervated by the Musculocutaneous N

Answer 15

Biceps Brachii, Coracobrachialis, Brachialis

Question 16

What signs would be apparent by damage to the Musculocutaneous N?

Answer 16

Weakness in supination and flexion at the elbow

Question 17

From which nerve roots does the Ulnar N arise?

Answer 17

C8/T1

Question 18

Which two nerves are a continuation of the medial cord?

Answer 18

The Ulnar and Median Nn

Question 19

Where is the Ulnar N most superficial - and therefore at most risk of damage?

Answer 19

As it courses posterior to the medial epicondyle of the humerus at the elbow

Question 20

The Ulnar N supplies all intrinsic muscles of the hand except which?

Answer 20

The muscles of the thenar eminence and the lumbricals to the index and middle fingers

Question 21

Name two deformities that would be apparent with damage to the Ulnar N

Answer 21

A ‘claw’ hand and atrophy of the interosseous muscles.

Question 22

The Median Nerve supplies what compartment of the arm?

Answer 22

Anterior

Question 23

Which nerve is affected in Carpal Tunnel Syndrome?

Answer 23

Median N

Question 24

If there is an apparent wrist drop - which nerve is most likely to have been damaged?

Answer 24

Radial N

Question 25

Which nerves arise from the lateral cord to the brachial plexus?

Answer 25

Musculocutaneous

Question 26

Which nerves arise from the posterior cord of the brachial plexus

Answer 26

Axillary and Radial Nn

Question 27

Which nerves arise from the medial cord of the BP?

Answer 27

Median (C5-7) and Ulnar (C8-T1)

Question 28

Which artery runs with the radial nerve in the radial groove?

Answer 28

The deep brachial artery

Question 29

At what point does the Axillary Nerve become the Brachial N?

Answer 29

At the lower border of Teres Maj

Question 30

The Brachial N bifurcates into what at the neck of the radius?

Answer 30

Ulnar and Radial Nn

Question 31

Which artery supplies the Anatomical Snuffbox?

Answer 31

Radial A

Question 32

The Radial A goes on to supply which palmar arch

Answer 32

Deep Palmar Arch

Question 33

the superficial palmar arch is an extension of which artery?

Answer 33

Ulnar A

Question 34

What are the boundaries of the anatomical snuffbox?

Answer 34

Tendons of : - EPL - EPB - Ad.PL

Question 35

The radial N innverates which compartment of the forearm

Answer 35

The posterior compartment - which contains all the wrist extensors