Appendicular Skeleton: Forelimb Muscles and Joints - Vocabulary Flashcards

Flashcards covering key terms related to joint orientation, movement, and forelimb muscles and their attachment points as discussed in the lecture notes.

Angle of the joint

The direction the joint faces, determined by bone anatomy; movement can increase (extension) or decrease (flexion) this angle.

Flexion

Movement that decreases the angle of a joint.

Extension

Movement that increases the angle of a joint.

Cranial side

The front/upper side of a joint; typically associated with muscles that extend the joint.

Caudal side

The back/lower side of a joint; typically associated with muscles that flex the joint.

Origin

The attachment site of a muscle that remains relatively fixed during contraction; usually proximal.

Insertion

The attachment site of a muscle that moves toward the origin during contraction; usually distal.

Agonist

The main muscle that produces a specific movement (the prime mover).

Antagonist

A muscle that opposes the action of the agonist in a movement.

Glenohumeral joint

Shoulder joint; ball-and-socket articulation between the scapula and humerus.

Elbow joint

Joint between the humerus, radius, and ulna; primarily allows flexion and extension.

Biceps brachii

Elbow flexor that crosses two joints (shoulder and elbow); originates on the scapula/humerus and inserts on the proximal radius.

Triceps brachii

Elbow extensor with multiple heads; antagonist to the biceps.

Serratus ventralis

Major thoracic girdle muscle with multiple rib/vertebra origins and insertion on the medial scapula; helps hold the forelimb to the body.

Latissimus dorsi

Large back muscle that extends/retracts the forelimb and helps draw the limb caudally; part of the thoracic girdle system.

Deep pectoral

Pectoral muscle from sternum to humerus; assists in pulling the limb toward the body (adduction).

Supraspinatus

Shoulder muscle that originates on the scapula and inserts on the humerus; contributes to extending/opening the shoulder angle and stabilizing the joint.

Infraspinatus

Shoulder muscle located caudal to the supraspinatus; stabilizes the joint and contributes to lateral rotation of the shoulder.