Arm Muscles Flashcards
Biceps brachii
O: Long head: supraglenoid tubercle of scapula; Short head: coracoid process of scapula
I: radial tuberosity, bicipital aponeurosis
N: Musculocutaneous n.
A: supination and flexion of forearm; flexion of arm (weakly)
Coracobrachialis
O: coracoid process of scapula
I: medial surface of mid-shaft of humerus
N: Musculocutaneous n.
A: flexion and adduction of arm
Brachialis
O: distal half of anterior humerus
I: coronoid process and tuberosity of ulna
N: Musculocutaneous n.
A: flexion of forearm
Pronator teres
O: medial epicondyle of humerus, coronoid process of ulna
I: lateral surface of radius
N: Median n.
A: pronation of forearm
Flexor carpi radialis (FCR)
O: medial epicondyle of humerus
I: base of 2nd metacarpal
N: Median n.
A: flexion and abduction of wrist
Palmaris longus
O: medial epicondyle of humerus
I: palmar aponeurosis
N: Median n.
A: flexion of wrist
Flexor digitorum superficialis (FDS)
O: medial epicondyle of humerus, coronoid process, shaft of radius
I: middle phalanges of digits 2-5
N: Median n.
A: flexion of PIP joints of digits 2-5
Flexor pollicis longus (FPL)
O: radius, interosseous membrane
I: distal phalanx of digit 1 (pollex/thumb)
N: Median n.
A: flexion of PIP and DIP joints of pollex
Flexor carpi ulnari (FCU)
O: medial epicondyle of humerus
I: pisiform, hook of hamate, base of 5th metacarpal
N: Ulnar n.
A: flexion and adduction of wrist
Flexor digitorum profundus (FDP)
O: ulna, interosseous membrane
I: distal phalanges of digits 2-5
N: Lateral: 1/2 of Median n.; Medial: 1/2 of Ulnar n.
A: flexion of DIP joints 2-5
Pronator quadratus
O: distal anterior ulna
I: distal anterior radius
N: Median n.
A: pronation of forearm
Triceps brachii
O: Long head: infraglenoid tubercle of scapula; Medial head: posterior humerus below radial groove; Short head: posterior humerus above radial groove
I: olecranon process of ulna
N: Radial n.
A: extension of forearm; Long head: extension of arm
Anconeus
O: lateral epicondyle of humerus
I: olecranon process/proximal ulna
N: Radial n.
A: accessory for extension of forearm
Brachioradialis
O: lateral supraepicondylar ridge of humerus
I: distal radius
N: Radial n.
A: flexion of forearm in mid-pronated position
Extensor carpi radialis longus
O: lateral supraepicondylar ridge of humerus
I: base of metacarpal 2
N: Radial n.
A: extension and abduction of wrist
Extensor carpi radialis brevis
O: lateral epicondyle of humerus
I: base of metacarpal 3
N: Radial n.
A: extension and abduction of wrist
Extensor digitorum
O: lateral epicondyle of humerus
I: extensor expansions of digits 2-5
N: Radial n.
A: extension of wrist; extension of all joints of digits 2-5
Extensor carpi ulnaris
O: lateral epicondyle of humerus, ulna
I: base of metacarpal 5
N: Radial n.
A: extension and adduction of wrist
Supinator
O: lateral epicondyle of humerus, ulna
I: proximal radius
N: Radial n.
A: supination of forearm
Abductor pollicis longus
O: ulna, radius, interosseous membrane
I: base of metacarpal 1
N: Radial n.
A: abduction of pollex
Extensor pollicis brevis
O: radius, interosseous membrane
I: proximal phalanx of digit 1 (pollex)
N: Radial n.
A: extension of pollex
Extensor polices longus
O: ulna, interosseous membrane
I: distal phalanx of digit 1 (pollex)
N: Radial n.
A: extension of pollex
Extensor indicis
O: ulna, interosseous membrane
I: extensor expansion of digit 2
N: Radial n.
A: extension of digit 2; extension of wrist
Extensor digiti minimi
O: lateral epicondyle of humerus
I: extensor expansion of digit 5
N: Radial n.
A: extension of wrist; extension of all joints of digit 5
Abductor pollicis brevis
O: trapezium, scaphoid, flexor retinaculum
I: proximal phalanx of digit 1 (pollex)
N: Median n. (via recurrent branch)
A: abduction of pollex
Flexor pollicis brevis (superficial head)
O: trapezium, scaphoid, flexor retinaculum
I: proximal phalanx of digit 1 (pollex)
N: Median n. (via recurrent branch)
A: flexion of pollex at MCP joint
Opponens pollicis
O: trapezium, scaphoid, flexor retinaculum
I: metacarpal 1
N: Median n. (via recurrent branch)
A: opposition of pollex
Flexor pollicis brevis (deep head)
O: trapezoid and capitate
I: proximal phalanx of digit 1 (pollex)
N: Ulnar n.
A: flexion of pollex at MCP joint
Adductor pollicis
O: Transverse head: metacarpal 3; Oblique head: capitate and metacarpals 2 & 3
I: medial base of proximal phalanx of digit 1 (pollex)
N: Ulnar n.
A: adduction of pollex
Abductor digiti minimi
O: pisiform
I: proximal phalanx of digit 5
N: Ulnar n.
A: abduction of digit 5
Flexor digiti minimi
O: hook of hamate, flexor retinaculum
I: proximal phalanx of digit 5
N: Ulnar n.
A: flexion of MCP joint of digit 5
Opponens digiti minimi
O: hook of hamate, flexor retinaculum
I: metacarpal 5
N: Ulnar n.
A: opposition of digit 5
Lateral Lumbricals
Lumbricals 1 & 2
O: lateral two tendons of FDP (Flexor digitorum profundus)
I: extensor expansions of digits 2-5
N: Median n.
A: flexion of MCP joints of digits 2-5, extension of PIP and DIP joints of digits 2-5
Medial Lumbricals
Lumbricals 3 & 4
O: medial three tendons of FDP (Flexor digitorum profundus)
I: extensor expansions of digits 2-5
N: Ulnar n.
A: flexion of MCP joints of digits 2-5, extension of PIP and DIP joints of digits 2-5
Palmar interosseous
O: sides of metacarpals 2, 4, and 5
I: proximal phalanges, and extensor expansions of digits 2, 4 and 5
N: Ulnar n.
A: adduction of digits 2, 4 and 5 (PAD); assist in flexion of MCP joints and extension of PIP/DIP joints
Dorsal interosseous
O: adjacent sides of two metacarpals
I: proximal phalanges, and extensor expansions of digits 2, 3 and 4
N: Ulnar n.
A: abduction of digits 2, 3 and 4 (DAB); assist in flexion of MCP joints and extension of PIP/DIP joints
