Upper Extremity Musculature

Comprehensive vocabulary flashcards covering the muscles of the upper extremity, including shoulder, arm, and forearm muscles with their origins, insertions, actions, and innervations.

Origin (Muscle Terminology)

The proximal attachment site of a muscle to a bone.

Insertion (Muscle Terminology)

The distal attachment site of a muscle to a bone.

Action (Muscle Terminology)

Movement of the body caused by the contraction of muscles, which moves the insertion point closer to the origin.

Innervation (Muscle Terminology)

The supply of peripheral nerves that stimulate muscles to contract or relax.

Deltoid m. (Anterior)

Originates on the clavicle and inserts into the deltoid tuberosity of the humerus. Actions include shoulder flexion and medial rotation along the long axis toward the midline. Innervated by the axillary nerve.

Deltoid m. (Posterior)

Originates on the spine of the scapula and inserts into the deltoid tuberosity of the humerus. Actions include shoulder extension and lateral rotation. Innervated by the axillary nerve.

Supraspinatus m.

A rotator cuff muscle originating in the supraspinous fossa of the scapula and inserting onto the greater tubercle of the humerus. Actions include shoulder stabilization and shoulder abduction (away from the midline). Innervated by the suprascapular nerve.

Infraspinatus m.

A rotator cuff muscle originating in the infraspinous fossa of the scapula and inserting onto the greater tubercle of the humerus. Actions include shoulder stabilization and shoulder lateral rotation. Innervated by the suprascapular nerve.

Teres minor m.

A rotator cuff muscle originating on the posterolateral scapula and inserting onto the greater tubercle of the humerus. Actions include shoulder stabilization and shoulder lateral rotation. Innervated by the axillary nerve.

Teres major m.

Originates on the inferior angle of the scapula and inserts into the intertubercular groove/sulcus of the humerus. Actions include shoulder extension and shoulder medial rotation. Innervated by the subscapular nerve.

Subscapularis m.

A rotator cuff muscle originating in the subscapular fossa and inserting onto the lesser tubercle of the humerus. Actions include shoulder stabilization and shoulder medial rotation. Innervated by the subscapular nerve.

Latissimus dorsi m.

Axial muscle acting on the appendicular skeleton. Originates from T7-L5, lower ribs, iliac crest, and thoracolumbar fascia; inserts into the intertubercular sulcus/groove of the humerus. Actions include shoulder extension, shoulder adduction, and shoulder medial rotation. Innervated by the thoracodorsal nerve.

Pectoralis major m.

Originates on the clavicle, sternum, and ribs 1-7; inserts into the intertubercular sulcus of the humerus. Actions include shoulder flexion (up to $90^\circ$), shoulder adduction, shoulder medial rotation, and extension from a flexed position. Innervated by the medial and lateral pectoral nerves.

Pectoralis minor m.

Originates on ribs 3-5 and inserts onto the coracoid process of the scapula. Actions include scapular abduction, downward rotation of the scapula, and depression of the scapula. Innervated by the medial and lateral pectoral nerves.

Coracobrachialis m.

Originates on the coracoid process and inserts onto the mid-medial humerus. Actions include shoulder flexion and medial rotation. Innervated by the musculocutaneous nerve.

Biceps brachii m.

Crosses two joints. Long head originates from the superior margin of the glenoid cavity, and short head originates from the coracoid process; inserts into the radial tuberosity. Actions include supination of the forearm, elbow flexion, weak shoulder flexion, and stabilization of the shoulder. Innervated by the musculocutaneous nerve.

Brachialis m.

Originates on the anterior distal humerus and inserts onto the coronoid process of the ulna. Action is elbow flexion. Innervated by the musculocutaneous and radial nerves.

Triceps brachii m.

Crosses two joints. Long head originates from the inferior margin of the glenoid, medial head from the posterior humerus, and lateral head from the posterior proximal humerus; inserts into the olecranon process. Actions include elbow extension and adduction of the humerus (long head). Innervated by the radial nerve.

Anatomical Root Words: Carpi, Digitorum, Pollicis, Indicis

Forearm/hand root terms where 'Carpi' refers to wrist, 'Digitorum' refers to digits, 'Pollicis' refers to thumb, and 'Indicis' refers to index finger.

Pronator teres m.

Originates on the medial epicondyle of the humerus and coronoid process of the ulna; inserts on the lateral surface of the radial shaft. Actions include pronation and weak elbow flexion. Innervated by the median nerve.

Flexor carpi radialis m.

Originates on the medial epicondyle of the humerus and inserts into the base of metacarpals 2-3. Actions include wrist flexion and radial deviation. Innervated by the median nerve.

Palmaris longus m.

Originates on the medial epicondyle of the humerus and inserts into the palmar aponeurosis and flexor retinaculum. Actions include wrist flexion and resisting shear forces when overlying skin is stressed. Innervated by the median nerve.

Flexor carpi ulnaris m.

Originates on the medial epicondyle of the humerus and inserts into the 5th metacarpal, hamate, and pisiform. Actions include wrist flexion and ulnar deviation. Innervated by the ulnar nerve.

MCP, PIP, and DIP Joints

Metacarpophalangeal joints (MCP), proximal interphalangeal joints (PIP), and distal interphalangeal joints (DIP) of the hand.

Flexor digitorum superficialis m.

Originates on the medial epicondyle of the humerus, UCL, and coronoid process; inserts into the middle phalanges 2-5. Actions include wrist flexion, and digit flexion at the metacarpophalangeal (MCP) and proximal interphalangeal (IP) joints. Innervated by the median nerve.

Flexor digitorum profundus m.

Originates from the proximal ulna and interosseous membrane; inserts into the distal phalanges of digits 2-5. Actions include wrist flexion, and flexion at the MCP, PIP, and DIP joints. Innervated by the median and ulnar nerves.

Flexor pollicis longus m.

Originates on the radius and interosseous membrane; inserts into the distal phalanx of digit 1. Action is flexing the thumb at the MCP and IP joints. Innervated by the median nerve.

Pronator quadratus m.

Originates on the anterior distal ulna and inserts onto the anterior distal radius. Action is pronation. Innervated by the median nerve.

Brachioradialis m.

Originates on the lateral supracondylar ridge of the humerus and inserts onto the styloid process of the radius. Action is elbow flexion. Innervated by the radial nerve.

Extensor carpi radialis longus m.

Originates on the lateral supracondylar ridge of the humerus and inserts into the base of the 2nd metacarpal. Actions include wrist extension and radial deviation/flexion. Innervated by the radial nerve.

Extensor carpi radialis brevis m.

Originates on the lateral epicondyle of the humerus and inserts into the base of the 3rd metacarpal. Actions include wrist extension and radial deviation/flexion. Innervated by the radial nerve.

Extensor digitorum m.

Originates on the lateral epicondyle of the humerus and inserts into the dorsal surface of phalanges 2-5. Actions include wrist extension, and MCP and PIP extension. Innervated by the radial nerve.

Extensor carpi ulnaris m.

Originates on the lateral epicondyle of the humerus and inserts into the base of the 5th metacarpal. Actions include wrist extension and ulnar deviation/flexion. Innervated by the radial nerve.

Anconeus m.

Originates on the lateral epicondyle of the humerus and inserts onto the lateral aspect of the olecranon. Action is elbow extension.

Extensor pollicis longus m.

Originates from the posterior ulna and interosseous membrane; inserts into the distal phalanx of digit 1. Actions include extending the MCP and IP of digit 1 (thumb), and adducting and laterally rotating digit 1. Innervated by the radial nerve.

Extensor pollicis brevis m.

Originates on the shaft of the radius and interosseous membrane; inserts into the proximal phalanx of digit 1 (thumb). Action is extending the MCP and IP of digit 1. Innervated by the radial nerve.

Extensor indicis m.

Originates on the posterior surface of the ulna and interosseous membrane; inserts into the middle and distal phalanges of the index finger. Actions include wrist extension and index finger extension. Innervated by the radial nerve.

Abductor pollicis longus m.

Originates on the posterior surface of the radius, ulna, and interosseous membrane; inserts into the trapezium and base of metacarpal 1. Actions include thumb abduction and thumb extension. Innervated by the radial nerve.