Thoracic Nerves Condensed

Question 1

Suprascapular N.

Answer 1

Innervates:
Supraspinatus
Infraspinatus

Question 2

Subscapular N.

Answer 2

Innervates:

Subscapularis

Question 3

Musculocutaneous N.

Answer 3

Innervates:
Biceps Brachii
Brachialis
Coracobrachialis

Skin over the medial aspect of the antebrachium

Question 4

Axillary N.

Answer 4

Innervates:
Deltoideus
Teres major
Teres minor

Skin over the lateral aspect of the brachium and over the cranial aspect of the antebrachium

Question 5

Radial N.

Answer 5

Innervates:
Triceps brachii
Extensor carpi radialis
Ulnaris lateralis
Common digital extensor
Lateral digital extensor

Skin over the craniolateral aspect of the antebrachium and the carpus and over the dorsal aspect of the forepaw

Question 6

Median N.

Answer 6

Innervates:
Flexor carpi radialis
Superficial digital flexor

Skin over the palmar aspect of the metacarpus and digits

Question 7

Ulnar N.

Answer 7

Innervates:
Flexor carpi ulnaris
Deep digital flexor
interosseous muscles - palmar branch

Skin

• caudal aspect of antebrachium
• palmar surface of carpus, metacarpus, and digits
• lateral surface of fifth digit

Question 8

Cranial pectoral N.

Answer 8

Innervates:

Superficial pectoral m.

Question 9

Caudal pectoral N.

Answer 9

Innervates:

deep pectoral m.

Question 10

Long thoracic N.

Answer 10

Innervates:

serratus ventralis m.

Question 11

Thoracodorsal N.

Answer 11

Innervates:

latissimus dorsi

Question 12

Lateral thoracic N.

Answer 12

Innervates:

cutaneous trunci

Question 13

What muscle group does the Ulnar N. and Median N. innervate?

Answer 13

Flexor muscles of carpus
Flexor muscles of digit
Interosseous muscles

Question 14

What muscle groups does the Radial N. innervate?

Answer 14

Extensor muscles of elbow
Extensor muscles of carpus and ulnaris lateralis
Extensor muscles of digits

Question 15

What muscle group does the Axillary N. innervate?

Answer 15

Flexor muscles of humeral joint

Question 16

What muscle group does the Musculocutaneous N. innervate?

Answer 16

Flexor muscles of cubital joint

Question 17

Injury to the Suprascapular N.

Answer 17

• Usually caused by trauma
• Paralysis of suprascapular n. results in atrophy of supraspinatus m. and infraspinatus m.
• Standing animal has abducted shoulder -> more pronouced during locomotion (“shoulder slip”)

Question 18

Injury to Musculocutaneous N.

Answer 18

• Uncommon

- would paralyze main flexor muscles of cubital joint

Question 19

Injury to Radial N.

Answer 19

• Avulsion of brachial plexus - most common cause is hit by car = trauma
• More proximal the damage, the more severe syndrome and more grave the prognosis
• Proximal to tricipital branches = paralysis of extensor muscles of elbow, carpus, and digit
• flaccid paralysis of effected thoracic limb
• non-weight bearing lameness
• foot is dragged with its dorsal surface on the ground
• Distal to tricipital branches = paralysis of extensor muscles of carpus and digit
• normal stance of shoulder and elbow are maintained
• affected manus knuckles over - rests dorsal surface of the toe on the gorund