Nerves Of The Forelimb

Question 1

Subscapular Nerve

Answer 1

Motor: active collateral ligaments of shoulder
Sensory: none
Muscle: subscapularis m.
[from C6, two small beaches to medial side of scapular]

Question 2

Musculocutaneous Nerve

Answer 2

Motor: shoulder extensors, elbow flexors
Sensory: medial antebrachium
Muscle: coracobrachialis, biceps brachii, brachialis.
(BBC nerve)
[from C6+7, three branches on medial brachium, communicating branch to median nerve, long branch down antebrachium]

Question 3

Axillary Nerve

Answer 3

Motor: flexors of shoulder
Sensory: lateral brachium and proximal lateral antebrachium
Muscle: deltoideus m. Teres major and teres minor mm.
[from C7+8, two branches caudal to shoulder joint innervating muscles. Cutaneous branch runs down lateral brachium]

Question 4

Radial Nerve

Answer 4

Motor: extensors of elbow, carpus and digits. Supinators
Sensory: craniolateral antebrachium and dorsal surface of paw
Muscle: triceps brachii, tensor fascia antebrachii, anconeus. Extensor carpi radialis, extensor carpi ulnaris. Common digital extensor, lateral digital extensor. Supinator and brachioradialis.
[from C7+8 T1, follows brachial groove of humerus with one branch, at elbow 4 branches. Nerve splits. Runs down radius (medial superficial nerve) At carpus divides again into metacarpal nerves –> dorsal digital nerves]

Question 5

Median Nerve

Answer 5

Motor: flexors of carpus and digits. Pronators
Sensory: palmar surface of paw (with ulnar n.)
Muscle: flexor carpi radialis. Superficial digital flexor. Deep digital flexor (with ulnar n.). Pronator terres and pronator quadratus.
[runs with ulnar n. from C8 + T1-2, no branches along brachium. At elbow 3 medial branches to flexors and communicating branch to musculocutaneous n. Runs down medial antebrachium –> digits]

Question 6

Ulnar Nerve

Answer 6

Motor: flexors of carpus and digits
Sensory: caudal antebrachium and, palmer surface of paw and lateral surface of 5th digit
Muscle: flexor carpi ulnaris, interosseus and deep digital flexor (with median n.)
[runs with median from C8 + T1-2, runs down medial side of humerus, branch over olecranon (funny bone). 3 branches on antebrachium to flexors, divides above accessory carpal bone –> palmer surface of digits]

Question 7

Suprascapular Nerve

Answer 7

Motor: Active collateral ligaments of shoulder
Sensory: none
Muscles: supraspinatus, infraspinatus
[from C6+7, two branches one on either side of spine of scapular, one descending branch to shoulder joint capsule]