Upper Limb Muscles - Vocabulary Flashcards

Flashcards covering the origin, insertion, innervation, and action of major shoulder, arm, forearm, and hand muscles as listed in the lecture notes.

Pectoralis major

Origin: Medial clavicle + manubrium + sternum + costal cartilage; Insertion: lateral lip of intertubercular sulcus (humerus); Innervation: medial and lateral pectoral nerves; Action: flexion, adduction and medial rotation of the humerus.

Pectoralis minor

Origin: ribs 3-5; Insertion: coracoid process; Innervation: medial pectoral nerve; Action: protracts and depresses scapula (accessory muscle of respiration).

Subclavius

Origin: upper border of 1st rib and costal cartilage; Insertion: inferior surface of the clavicle; Innervation: nerve to subclavius; Action: anchors and depresses clavicle.

Serratus anterior

Origin: ribs 1-9; Insertion: medial border of scapula, costal surface; Innervation: long thoracic nerve; Action: fixes scapula to thoracic wall, abducts the humerus; works with trapezius for arm abduction (90–180 degrees).

Deltoid

Origin: Anterior — lateral clavicle; Middle — acromion process of scapula; Posterior — spine of scapula; Insertion: deltoid tuberosity of humerus; Innervation: axillary nerve; Action: Anterior: arm flexion and internal rotation; Middle: abduction of arm (15–90 degrees); Posterior: arm extension and lateral rotation.

Supraspinatus

Origin: supraspinous fossa of scapula; Insertion: greater tubercle of humerus; Innervation: suprascapular nerve; Action: first 15 degrees of arm abduction.

Infraspinatus

Origin: infraspinous fossa of scapula; Insertion: greater tubercle of humerus; Innervation: suprascapular nerve; Action: external rotation of humerus.

Teres minor

Origin: lateral border of scapula; Insertion: greater tubercle of humerus; Innervation: axillary nerve; Action: external rotation of humerus.

Subscapularis

Origin: subscapular fossa of scapula; Insertion: lesser tubercle of humerus; Innervation: upper and lower subscapular nerves; Action: internal rotation of humerus.

Teres major

Origin: inferior angle of scapula; Insertion: crest of lesser tubercle of humerus; Innervation: lower subscapular nerve; Action: extension, adduction and internal rotation of humerus (same as latissimus dorsi).

Biceps brachii

Origin: Short head — coracoid process; Long head — supraglenoid tubercle of scapula; Insertion: radial tuberosity of radius via the bicipital aponeurosis; Innervation: musculocutaneous nerve (C5–C7); Action: flexion and supination of forearm; flexion of arm (long head).

Coracobrachialis

Origin: coracoid process; Insertion: middle 1/3 of humerus; Innervation: musculocutaneous nerve (C5–C7); Action: flexion + adduction of arm.

Brachialis

Origin: anterior midshaft of humerus; Insertion: coronoid process of ulna; Innervation: musculocutaneous nerve (C5–C7); Action: primary flexor of forearm.

Triceps brachii

Origin: Long head — infraglenoid tubercle of scapula; Lateral — posterior midshaft of humerus; Medial — posterior midshaft of humerus; Insertion: common tendon to olecranon process of ulna; Innervation: radial nerve (C5–C8, T1); Action: all heads extend elbow; long head also extends the arm.

Anconeus

Origin: lateral epicondyle; Insertion: olecranon process; Innervation: radial nerve (C5–C8, T1); Action: weak forearm extensor, stabilizes the elbow joint.

Pronator teres

Origin: Medial epicondyle of humerus; Insertion: anterior radius; Innervation: median nerve; Action: pronation + weak flexion of forearm.

Flexor carpi radialis

Origin: Medial epicondyle of humerus; Insertion: radial side of wrist; Innervation: median nerve; Action: wrist flexion + abduction (radial deviation).

Palmaris longus

Origin: Medial epicondyle of humerus; Insertion: palmar aponeurosis; Innervation: median nerve; Action: wrist flexion.

Flexor carpi ulnaris

Origin: Medial epicondyle of humerus; Insertion: ulnar side of wrist; Innervation: ulnar nerve; Action: wrist flexion + adduction.

Flexor digitorum superficialis

Origin: Medial epicondyle of humerus + anterior radius; Insertion: bases of middle phalanges of digits 2–5; Innervation: median nerve; Action: flexion of fingers (at PIP joints).

Pronator quadratus

Origin: distal anterior ulna; Insertion: distal anterior radius; Innervation: anterior interosseous nerve; Action: pronation of forearm.

Flexor digitorum profundus

Origin: anterior ulna + interosseous membrane; Insertion: base of distal phalanges 2–5; Innervation: lateral portion (digits 2–3) via anterior interosseous nerve; medial portion (digits 4–5) via ulnar nerve; Action: flexion of fingers.

Flexor pollicis longus

Origin: anterior radius; Insertion: distal phalanx of digit 1; Innervation: anterior interosseous nerve; Action: flexion of the thumb.

Brachioradialis

Origin: supraepicondylar ridge (lateral); Insertion: distal radius (anterior); Innervation: radial nerve (proper); Action: flexion of forearm (wrist does not move).

Extensor carpi radialis longus

Origin: supraepicondylar ridge (lateral); Insertion: dorsal base of 2nd metacarpal; Innervation: radial nerve (proper); Action: wrist extension + abduction.

Extensor carpi radialis brevis

Origin: lateral epicondyle of humerus; Insertion: dorsal base of 3rd metacarpal; Innervation: posterior interosseous nerve; Action: wrist extension + abduction.

Extensor digitorum

Origin: lateral epicondyle of humerus; Insertion: extensor expansions of digits 2–5; Innervation: posterior interosseous nerve; Action: extension of digits.

Extensor digiti minimi

Origin: lateral epicondyle of humerus; Insertion: extensor expansion of digit 5; Innervation: posterior interosseous nerve; Action: extension of digit 5.

Extensor carpi ulnaris

Origin: lateral epicondyle of humerus; Insertion: ulnar side of wrist; Innervation: posterior interosseous nerve; Action: wrist extension + adduction.

Abductor pollicis longus

Origin: posterior ulna, radius and interosseous membrane; Insertion: base of MC1; Innervation: posterior interosseous nerve; Action: thumb abduction.

Extensor pollicis brevis

Origin: posterior radius and interosseous membrane; Insertion: base of proximal phalanx of thumb; Innervation: posterior interosseous nerve; Action: thumb extension.

Extensor pollicis longus

Origin: posterior ulna and interosseous membrane; Insertion: base of distal phalanx of thumb; Innervation: posterior interosseous nerve; Action: thumb extension.

Extensor indicis

Origin: posterior ulna and interosseous membrane; Insertion: extensor expansion of digit 2; Innervation: posterior interosseous nerve; Action: extension of 2nd digit.

Supinator

Origin: posterior ulna; Insertion: lateral and anterior radius; Innervation: deep branch of radial nerve; Action: forearm supination.

Abductor pollicis brevis

Origin: nan; Insertion: nan; Innervation: Recurrent branch of median nerve; Action: abducts the thumb.

Flexor pollicis brevis

Origin: nan; Insertion: nan; Innervation: superficial head → recurrent branch of median nerve; Deep head → deep branch of ulnar nerve; Action: nan.

Opponens pollicis

Origin: nan; Insertion: nan; Innervation: Recurrent branch of median nerve; Action: nan.

Adductor pollicis

Origin: nan; Insertion: nan; Innervation: deep branch of ulnar nerve; Action: nan.

Abductor digiti minimi

Origin: nan; Insertion: nan; Innervation: deep branch of ulnar nerve; Action: nan.

Flexor digiti minimi brevis

Origin: nan; Insertion: nan; Innervation: deep branch of ulnar nerve; Action: nan.

Opponens digiti minimi

Origin: nan; Insertion: nan; Innervation: deep branch of ulnar nerve; Action: nan.

Lumbricals

Origin: nan; Insertion: nan; Innervation: 1st and 2nd → median nerve; 3rd and 4th → deep branch of ulnar nerve; Action: flex MCP joints, extend PIP joints.

Palmar interossei

Origin: nan; Insertion: nan; Innervation: deep branch of ulnar nerve; Action: adducts fingers.

Dorsal interossei

Origin: nan; Insertion: nan; Innervation: deep branch of ulnar nerve; Action: abducts fingers.