Canine forelimb PDF

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Lecture notes on the anatomy of the canine forelimb...

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Lecture 1

Canine forelimb Skeletal anatomy

The scapula • Supra = above • Infra = Below • The horse does not have an acromion • The glenoid cavity articulates with the head of the humerous • Supraglenoid tubercule attaches biceps The humerous • Greater tubercle = Lateral • Lesser tubercle = Medial • The epicondyle is found on the sides of the cranial aspect • The condyles are found cranially and articulate with the radius and ulna • The deltoid muscle attaches to the deltoid tuberosity • In dogs there is a sypratrochlea fossa and in cats there is a supracondylar foramen which is found in the medial aspect and allows the brachial artery and median nerve to pass through Radius and Ulna • There is an medial and lateral coronoid process • Trochlear notch • Tricep muscle attaches to the olecranon • Anconeal process is found above the trochlear notch Carpal and metacarpal bones • Proximal (Named) and distal (numbered) row of carpal bones • The distal row articulate with metacarpal bones • Radial carpal bone is fused in dogs but not in other species • There are up to 5 metacarpal bones • In each phalange there are 3 bones going from distal to proximal • Seasimoid bones sit in the palmar aspect Muscles of the forelimb • Forelimb is attached to the body only by muscles • There is no body attachment so is called a synsarcosis • Extrinsic muscles attach from the limb to the body • Intrinsic muscles both originate and insert within the same limb

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Lecture 1

Extrinsic muscles 1. Trapezius = has 2 bellies and attaches from the scapular spine to the cervical midline cranially and thoracic dorsal midline caudally 2. Omotransversarius = From the distal scapular spine to the transverse processes of c1-c2 3. Brachiocephalicus = a) cleidobrachialis an b) Cleidocephalicus 4. Lattisimus Dorsi = Large fan shaped muscle from trees major tuberosity on the caudal humerous to the thoracolumbar fascia and last 2-3 ribs 5. Pectorals = a) superficial - first 2-3 sternebrae to greater tubercle, b) deep - whole sternum to lesser tubercle and brachial fascia 1. Rhomboideus = Dorsal midline to proximomedial border of the scapula 2. Serratis ventralis = Lateral thoracic wall/neck ventrally to the medial surface of the scapula • Trunk suspension from forelimbs: - Rhomboideus - Serratis Ventralis - Pectorals Musculature acting on the shoulder • Lateral shoulder support muscles: 1. Supraspinatus = Supraspinous fossa to greater tubercle and lateral supports the shoulder 2. Infraspinatus = Infraspinatus fossa to lateral greater tubercle and supply lateral support • Suprascapular nerve innervates the muscle • Shoulder flexor muscles 1. Deltoideus = Laterally has 2 heads and the acromion and scapula spine to deltoid tuberosity 2. Teres major = Medial and the caudal scapula margin to medial humeral diaphysis • Axillary nerve innervates the muscle • Medial shoulder support muscles 1. Subscapularis = Subscapular fossa to medial humeral neck, the medial joint support to stop abduction 2. Coracobrachialis • Subscapular nerve innervates the muscles • Shoulder extensors 1. Biceps brachii = Supraglenoid tubercle to proximal radius and ulna, its primarily a flexor of the elbow and the proximal tendon prone to tendon strains • Musculocutaneous nerve innervates the muscles Shoulder joint • Spheroidal joint (ball and socket) • Mostly flexion and extension occurs • Minimal ab/adduction • Lateral and medial glenohumeral ligaments • The lateral is linear and medial is larger and y shaped • Muscles provide significant contribution to support but joint capsule is very important Neurological input to forelimb • Brachial plexus = nerves for forelimb arise from C6 - T2 vertebrae in most animals

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