Cranial to caudal: C5, C6, T2, T3
Dark purple: T2 lateral cutaneous branch
Light purple: Axillary nerve
Grey: T3 lateral cutaneous branch
Light blue: C5 ventral cutaneous branch
Turquoise: Brachiocephalic nerve (C6)
Orange: Musculocutaneous (C6, 7, 8)
Yellow: Ulnar nerve (C8, T1, 2)
Green: Radial nerve (C7, 8, T1, 2)
Autonomous zone palmar surface of the paw
Overlap of cutaneous zones of median (C8, T1) and ulnar (C7, 8, T1)
What segment makes up the brachiocephalic nerve?
What is the autonomous innervation of this nerve?
Brachiocephalic nerve = C6 (7)
Autonomous zone: craniolateral shoulder
Suprascapular and subscapular nerve:
- spinal cord segments
- muscles
- actions
Suprascapular C6, 7
- Supraspinatus - extends the shoulder, advances the limb
- Infraspinatus - lateral rotation and abduction of the proximal humerus
Subscapular C6, 7
- Subscapularis - shoulder flexion
Musculocutaneous and Axillary nerves:
- spinal cord segments
- muscles
- actions
Musculocutaneous (C6, 7, 8)
- biceps brachii - extends the shoulder, flexes elbow
- Brachialis - flexes elbow
- coracobrachialis - extends/adducts shoulder
Axillary (C6, 7, 8)
- Deltoid - flex shoulder
- Teres major, minor - “
- subscapularis - “
Radial nerve
- Spinal cord segments
- Muscles
- Actions
Radial nerve (C7, 8, T1, 2)
- Triceps - extends the elbow
- Extensor carpi radialis - extends carpus and digits
- Ulnaris lateralis - abducts/laterally rotates the carpus
- Common and lateral digital extensors - extends digits II-V (common) and III - V (lateral)
- Overall - extends elbow, carpus, digits
Median nerve
- spinal cord segments
- muscles
- actions
Median nerve (C8, T1)
- Flexor carpi radialis - flexes carpus
- Superficial digital flexor - flexes digits II - V
- Deep digital flexor - flexes carpus and digits
- Overall: Flexes carpus and digits
Ulnar nerve
- spinal cord segments
- muscles
- actions
Ulnar nerve (C8, T1, 2)
- Flexor carpi ulnaris - flexes carpus and digits
- deep digital flexor - “ “ “
Muscles of the lateral scapula (4)
Muscles of the medial scapula (2)
Innervation?
Lateral scapula - innervated by suprascapular and axillary nerves
- Supraspinatus
- Infraspinatus
- Deltoid
- Teres minor
Medial scapula - innervated by subscapular and axillary nerves
- Subscapularis
- Teres major
Cranial brachial muscles (3)
Caudal brachial muscles (1)
Innervation?
Cranial brachial muscles - musculocutaneous nerve
- Biceps brachii
- Brachialis
- Coracobrachialis
Caudal brachial muscles - radial nerve
- Triceps
Craniolateral antebrachial muscles (4)
Caudolateral antebrachial muscles (4)
Craiolateral antebrachial muscles - innervated by radial nerve
- Extensor carpi radialis
- Ulnaris lateralis
- Common digital extensor
- Lateral digital extensor
Caudolateral antebrachial muscles - innervated by ulnar nerve and median nerve
- Flexor carpi radialis
- Superficial digital flexor
- Deep digital flexor
- Flexor carpi ulnaris
