Thoracic Limb Flashcards
What nerves usually make up the brachial plexus?
C6, C7, C8, T1, T2
What artery supplies the superficial pectorals?
External thoracic
What does the external thoracic artery supply?
Superficial pectorals
What artery supplies the deep pectorals?
Lateral thoracic
What does the lateral thoracic artery supply?
Deep pectorals
What artery supplies the latissimus dorsi?
Thoracodorsal
What does the thoracodorsal artery supply?
Latissimus dorsi
Cranial circumflex humeral artery supplies what?
Proximal part of the biceps
What arteries supply the cubital joint?
Transverse cubital, collateral ulnar
What arteries supply the triceps?
Caudal circumflex humeral, deep brachial, collateral ulnar
What arteries supply the deep palmar arch?
Caudal interosseous and a small branch of the radial
What arteries supply the superficial palmar arch?
Median and a small part of the superficial branch of the caudal interosseous
What does the ulnar artery supply?
Flexor muscles
What does the median artery supply?
principal blood source for the paw, superficial palmar branch
What does the radial artery supply?
Deep palmar arch
What does the deep antebrachial artery supply?
Flexor muscles of carpal and digital joints
In the forepaw, the superficial arteries go to…?
Common digital arteries (dorsal and palmar respectively)
In the forepaw, the deep arteries go to…?
metacarpal arteries (dorsal and palmar respectively)
What is the dorsal carpal rete?
It is a vascular network forming metacarpal arteries
What is the deep venous system formed by?
Tributaries of the axillary vein
What are the connections between the superficial and deep venous system?
Median cubital vein and axillobrachial vein
What veins exit into the external jugular?
Cephalic and omobrachial
What are the vessels associated with the superficial lymph node?
Afferent: Most of thoracic limb except medial arm, forearm, shoulder; drain skin of caudal head, ear, lateral neck surface
Efferent: Thoracic duct on left side, right tracheal trunk and external jugular vein
What are the vessels associated with the constant axillary lymph node?
Afferent: first three mammary glands, skin of the shoulder and arm, all bones except digits, all joints above digits, thoracic limb muscles, accessory axillary lymph node
Efferent: external jugular vein, thoracic duct on left side and both tracheal trunks
What are the vessels associated with the inconstant accessory axillary lymph node?
Afferent: first three mammary glands, skin of lateral and ventral thoracic wall, lateral and medial regions of shoulder, arm and elbow
Efferent: axillary lymph node
What do the spinal nerves contain?
general somatic afferent, general somatic efferent, post ganglionic sympathetic neurons and autonomic afferents
What nerves originate from the brachial plexus?
Subscapular, thoracodorsal, lateral thoracic, long thoracic, cranial pectoral, caudal pectoral, suprascapular, axillary, musculocutaneous, radial, median, ulnar
What nerves have cutaneous branches?
Axillary, musculocutaneous, radial, median, and ulnar
How do you do clinical testing of the cutaneous sensation?
Two step: Small fold of skin is grasped. Then, progress to skin pinch gradually increased until response occurs
What are the extrinsic muscles of the thoracic limb?
Latissimus dorsi, rhomboideus, trapezius, brachiocephalicus, both the superficial and deep pectorals, omotransversarius
What nerves of the brachial plexus innervate the extrinsic muscles?
Cranial and caudal pectoral, long thoracic, thoracodorsal, and lateral
What does the cranial pectoral innervate?
Superficial pectoral
What does the caudal pectoral innervate?
Deep pectoral
What does the long thoracic nerve innervate?
Serratus ventralis
What does the thoracodorsal nerve innervate?
Latissimus dorsi
What does the lateral thoracic nerve innervate?
Cutaneous trunci and preputial
What is the panniculus reflex?
It’s a part of the lateral thoracic nerve; used to localise a spinal cord lesion from C8-L3, sensory stimulus is mild skin compression–>twitch of cutaneous trunci from lumbar and thoracic spinal nerves, specifically the GSE neurons that exit the ventral grey columns
What nerves innervate the intrinsic muscles of the thoracic limb?
Suprascapular, subscapular, musculocutaneous, axillary, median, radial, ulnar
What does the suprascapular nerve innervate and what happens when it is injured?
Supraspinatus and infraspinatus; it causes atrophy of these two muscles
What does the subscapular nerve innervate?
Subscapularis
What are the flexor muscles of the cubital joint?
Biceps brachii and brachialis
What does the musculocutaneous nerve innervate?
Proximal muscular branch: biceps brachii, communicating branch: distal end of the brachium to join the median nerve, distal muscular branch: brachialis muscle, medial cutaneous antebrachial nerve: skin of the medial antebrachium, coracobrachialis
What are the flexor muscles of the humeral joint?
Teres major, teres minor, deltoideus
What does the axillary nerve innervate?
flexor muscles of the humeral joint, skin over lateral brachium and cranial antebrachium
What are the extensor muscles of the cubital joint?
Triceps brachii, tensor fascia antebrachii, anconeus
What are the carpi and digital extensor muscles?
Extensor carpi radialis, common digital extensor, lateral digital extensor, abductor digiti I longus
What does the radial nerve innervate?
Tricipital branches to extensor muscles of cubital joint, superficial branch: lateral cutaneous antebrachial nerve innervates craniolateral skin of antebrachium and carpus, dorsal common digital nerves innervate digits 2-4 on metacarpus, medial branch–>dorsal common digital nerve for 1 metacarpal; deep branch: under supinator and innervates extensor muscles of carpal and digital joints; ulnaris lateralis too, skin on dorsal forepaw
What happens when the radial nerve is damaged?
If hit by car which is most common, the more proximal the injury the more severe the damage. Proximal to tricipital branches: paralysis of extensor muscles of elbow, carpus, digits–>flaccid paralysis of limb, non-weight bearing lameness and dorsal part of foot dragged. Distal to tricipital branches: paralysis of extensor muscles of carpus and digits, normal stance of elbow and shoulder but the dorsal part knuckles over
What are the flexor muscles of the carpus and digital joints?
Flexor carpi radialis, flexor carpi ulnaris, superficial digital flexor, deep digital flexor, pronotor teres, pronator quadratus, ulnaris lateralis
What does the median nerve innervate?
flexor carpi radialis, superficial digital flexor, deep digital flexor, pronator teres, pronator quadratus, palmar aspect of the metacarpus and digits of the skin
What does the ulnar nerve innervate?
Flexor carpi ulnaris, deep digital flexor, palmar branch of the interosseous muscles; caudal cutaneous antebrachial branch innervates caudal antebrachial skin, palmar branch goes to the palmar surface of carpus, metacarpus, and digits, dorsal branch to the lateral surface of the 5th digit
In the forepaw, the superficial digital nerves go to…?
Dorsal and palmar common digital nerves
In the forepaw, the deep digital nerves go to…?
palmar metacarpal nerves; NO DORSAL BRANCH like in the arteries
