ANATOMY - Forelimb Nerve, Vascular and Lymph Supply

Question 1

Which spinal nerves make up the brachial plexus?

Answer 1

C6, C7, C8, T1 and T2

Question 2

What are two common causes of damage to the brachial plexus?

Answer 2

Avulsion
Neoplasms

Question 3

Which three extrinsic muscles of the forelimb are supplied by the brachial plexus?

Answer 3

Latissimus dorsi muscle
Serratus ventralis muscle
Pectoral muscles

Question 4

Which seven peripheral nerves emerge from the brachial plexus to supply the intrinsic muscles of the forelimb?

Answer 4

Suprascapular nerve
Subscapular nerve
Axillary nerve
Musculocutaneous nerve
Median nerve
Ulnar nerve
Radial nerve

Question 5

What is the function of the suprascapular nerve?

Answer 5

Motor innervation of the supraspinatous muscle and infraspinatous muscle

Question 6

What is the function of the subscapular nerve?

Answer 6

Motor innervation of the subscapularis muscle

Question 7

What are the consequences of damage to the suprascapular and subscapular nerves?

Answer 7

Damage to the suprascapular and subscapular nerves would cause the supraspinatous, infraspinatous and subscapularis muscles to lose tension and no longer provide support to the shoulder joint

Question 8

What are the functions of the axillary nerve?

Answer 8

Innervation of the deltoideus and teres major muscles and cutaneous sensation of the lateral omo (shoulder region) and brachium regions

Question 9

What are the consequences of damage to the axillary nerve?

Answer 9

Damage to the axially nerve would lead to a loss of cutaneous sensation at the lateral omo (shoulder region) and brachium regions

Question 10

Why would damage to the axillary nerve not result in the loss of shoulder flexion?

Answer 10

Latissimus dorsi and the long head of the triceps brachii muscles are both shoulder flexors and would compensate

Question 11

What are the functions of the musculocutaneous nerve?

Answer 11

Innervation of the biceps brachii muscle and the brachialis muscle. Also provides cutaneous sensation to the medial antebrachium region

Question 12

What are the consequences of damage to the musculocutaneous nerve?

Answer 12

Loss of elbow flexion and cutaneous sensation to the medial antebrachium region

Question 13

What are the functions of the median and ulnar nerves?

Answer 13

Innervation of the the flexor carpi ulnaris muscle, superficial digital flexor muscle and deep digital flexor muscle ,and cutaneous sensation to the caudal/palmer limb and the dorsal surface of the 5th digit

Question 14

What are the consequences of damage to the median and ulnar nerves?

Answer 14

Loss of carpal and digital flexion and a loss of cutaneous sensation to the caudal/palmer limb and the dorsal surface of the 5th digit

Question 15

What are the functions of the radial nerve?

Answer 15

Innervation of the triceps brachii muscle, extensor carpi radialis muscle, extensor capri ulnaris muscle and the common digital extensor muscle. Also provides cutaneous sensation to the cranial/dorsal limb (except the 5th digit)

Question 16

(T/F) The radial nerve is very prone to isolated damage

Answer 16

TRUE.

Question 17

What is the most common cause of radial nerve damage?

Answer 17

Humerus fracture

Question 18

What are the consequences of proximal radial nerve damage?

Answer 18

Damage to the proximal radial nerve would lead to a loss of elbow, carpal and digital extension and a loss of cutaneous sensation to the cranial/dorsal limb (except the fifth digit)

Question 19

What are the consequences of distal radial nerve damage?

Answer 19

Damage to the distal radial nerve would lead to a loss of carpal and digital extension and a loss of cutaneous sensation to the cranial/dorsal limb (except 5th digit)

Question 20

What is a common consequence of the loss of cutaneous sensation seen in radial nerve damage?

Answer 20

Self-mutilation

Question 21

Describe the organisation of the forelimb arterial supply

Answer 21

The arterial supply for the forelimb is one major artery that runs from the trunk to the forelimb, where the name of the artery changes depending on the region of the forelimb it is located

Question 22

What are the four main regions of forelimb arterial supply?

Answer 22

Subclavian artery
Axillary artery
Brachial artery
Median artery

Question 23

Which vein of the forelimb is the most clinically relevant?

Answer 23

Cephalic vein

Question 24

What are the two main lymph nodes present in the forelimb?

Answer 24

Prescapular lymph node
Axillary lymph node

Question 25

Which lymph node present in the forelimb is palpable?

Answer 25

Prescapular lymph node