Thoracic Limb Joints Vet Prep PDF Spring 2024

Vet Prep Structural and Functional Biology Dr. Melissa Kehl Thoracic Limb Joints Courtesy of Dr. Terri Clark Learning Objectives: Describe the bones that make up the shoulder, elbow and carpus. Describe the important boney prominences / structures that make up these joints. Utilize scientific termin...

Vet Prep Structural and Functional Biology Dr. Melissa Kehl Thoracic Limb Joints Courtesy of Dr. Terri Clark Learning Objectives: Describe the bones that make up the shoulder, elbow and carpus. Describe the important boney prominences / structures that make up these joints. Utilize scientific terminology necessary to describe these joints movements and directional terms. Give examples of muscles which cause action at these joints; as well as their individual origin and insertions. ❖Species differences in this lecture are NOT required knowledge at this point; however, they will be important in the future. Species difference provided in this lecture are only to encourage critical thinking. Lateral view SCAPULA Medial view Left scapula of the dog. 2 - spine; 3 - supraspinous fossa; 4 - infraspinous fossa; 6 - supraglenoid tubercle; 7 - acromion; 12 - glenoid cavity DOG HUMERUS Left humerus 1 - Greater tubercle 2 – head 3 - lesser tubercle 4 - teres major tuberosity 5 - deltoid tuberosity 8 - medial epicondyle 9 – condyle 10 - lateral epicondyle Caudal view Cranial view Bones of the Shoulder Joint Head of the humerus Synovial- ball and socket joint Glenoid cavity of the scapula Shoulder joint AKA Glenohumeral joint AKA Scapulohumeral joint “Glenoid” → Greek “Socket” 1 Scapula 5 humerus 6 joint capsule Lateral View Left front Supraspinatus Origin: Supraspinous Fossa Insertion: Greater Tubercle of Humerus Action: Extension of the shoulder Medial View Left front Teres Major Origin: Caudal border of scapula Insertion: Teres Major Tuberosity Action: Shoulder Flexion caudal cranial Elbow joint 3 joints: humeroradial, humeroulnar and proximal radioulnar. Elbow joint of the dog 5 - Distal humerus 11 - lateral collateral ligament 13 – radius 14 - ulna 15 - joint capsule; 19 - biceps brachii 21 - medial collateral ligament. Lateral view Medial view cranial view Radius condyle Ulna cranial view lateral view humerus radius ulna Dog 1 olecranon 2 anconeal process 3 trochlear notch 6 lateral styloid process, ulna 8 medial styloid process, radius 9. Condyle of humerus craniolateral cranial cranial caudal Lateral View Left front Triceps Brachii Origin: Caudal border of scapula and proximal humerus Insertion: Olecranon of Ulna Action: Extension of the elbow flex the shoulder Biceps Brachii Origin: Supraglenoid tubercle of scapula Insertion: Radial and Ulnar Tuberosity (cranial, medial) Action: Flex the elbow Extend the shoulder Cranial View Medial View Supinator Cranial view Origin: Lateral Epicondyle of humerus Insertion: Cranial radius Action: Supinate antebrachium (turn inward) Pronator teres Origin: Medial Epicondyle of humerus Insertion: Cranial radius Action: Pronate the antebrachium (turn outward) Carpal Joints Antebrachiocarpal joint between the distal radius / ulna and the carpal bones. Middle carpal joint between the two rows of carpal bones Carpometacarpal joint between the distal row of carpal bones and the metacarpals. Flexion of the carpus A = antebrachial carpal joint; B= middle carpal joint; C = carpometacarpal joint Flexor carpi ulnaris Origin: Medial epicondyle of the humerus and olecranon Insertion: Accessory carpal bone Action: Flex the Carpus Caudal View Left front Extensor carpi radialis Origin: Lateral epicondyle of the humerus Extensor carpi radialis Lateral View Left front Insertion: Metacarpal bones II and III Action: Extend the Carpus