Arm & Forearm Flashcards
biceps brachii origin
Short head: tip of coracoid process of scapula
Long head: supraglenoid tubercle of scapula
biceps brachii insertion
tuberosity of radius & fascia of forearm
biceps brachii innervation
Musculotaneous nerve (C5, C6, C7)
biceps brachii action
supinates forearm and flexes forearm, short head resists dislocation of shoulder
coracobrachialis origin
tip of the coracoid process of scapula
coracobrachalis insertion
middle third of medial surface of humerus
coracobrachialis innervation
Musculocutaneous nerve (C5, C6, C7)
coracobrachialis action
helps flex and adduct arm; resists dislocation of shoulder
brachialis origin
distal half of anterior surface of humerus
brachialis insertion
coronoid proces and tuberosity ulna
brachialis innervation
musculotaneous nerve (C5, C6) and radial nerve (C5, C7)
brachialis action
flexes forearm in all positions
triceps brachii origin
Long head: infraglenoid tubercle of scapula
Lateral Head: posterior surface of humerus, superior to radial groove
Medial head: posterior surface of humerus, inferior to radial groove
triceps brachii insertion
proximal end of olecranon of ulna and fascia of forearm
triceps brachii innervation
radial nerve (C6, C7, C8)
triceps brachii action
chief extensor of forearm; long head resists dislocation of humerus; especially important during adduction
anconeus origin
lateral epicondyle of humerus
anconeus insertion
lateral surface of olecranon and superior part of posterior surface of ulna
anconeus innervation
radial nerve (C7, C8, T1)
anconeus action
assists triceps in extending forearm; stabilizes elbow joint; may abduct ulna during pronation
pronator teres (ulnar head) origin
coronoid process
pronator teres (ulnar head & humeral head) insertion
middle of convexity of lateral surface of radius
pronator teres (ulnar head & humeral head) innervation
Median nerve (C6, C7)
pronator teres (ulnar head & Humeral head) action
pronates and flexes forearm (at elbow)
pronator teres (humeral head) origin
medial epicondyle of humerus
flexor carpi radialis (FCR) origin
medial epicondyle of humerus
flexor carpi radialis (FCR) insertion
base of 2nd metacarpal
flexor carpi radialis (FCR) innervation
median nerve (C6, C7)
flexor carpi radialis (FCR) action
flexes and abducts hand (at wrist)
palmaris longus origin
medial epicondyle of humerus
palmaris longus insertion
distal half of flexor retinaculum and apex of palmar aponeurosis
palmaris longus innervation
median nerve (C7, C8)
palmaris longus action
flexes hand (at wrist) and tenses palmar aponeurosis
flexor carpi ulnaris (FCU) (humeral head) origin
medial epicondyle of humerus
flexor carpi ulnaris (FCU) (ulnar & humeral head) insertion
pisiform, hook of hamate, 5th metacarpal
flexor carpi ulnaris (FCU) (ulnar & humeral head) innervation
Ulnar nerve (C7, C8)
flexor carpi ulnaris (FCU) (ulnar & humeral head) action
flexes and adducts hand (at wrist)
flexor carpi ulnaris (FCU) (ulnar head) origin
olecranon and posterior border of ulna (via aponeurosis)
flexor digitorum profundus (FDP) (medial and lateral) origin
proximal three quarters of medial and anterior surfaces of ulna and interosseous membrane
flexor digitorum profundus (FDP) (medial) insertion
bases of distal phalanges of 4th and 5th digits
flexor digitorum profundus (FDP) (medial) innervation
ulnar nerve (C8, T1)
flexor digitorum profundus (FDP) (medial) action
flexes distal phalanges 4 and 5 at distal interphalangeal joints
flexor digitorum profundus (FDP) (lateral) insertion
bases of distal phalanges of 2nd and 3rd digits
flexor digitorum profundus (FDP) (lateral) innervation
anterior interosseous nerve, from median nerve (C8, T1)
flexor digitorum profundus (FDP) (lateral) action
flexes distal phalanges 2 and 3 at distal interphalangeal joints
flexor pollicis longus (FPL) origin
anterior surface of radius and adjacent interosseous membrane
flexor pollicis longus (FPL) insertion
base of distal phalanx of thumb
flexor pollicis longus (FPL) innervation
anterior interosseous nerve, from median nerve (C8, T1)
flexor pollicis longus (FPL) action
flexes phalanges of 1st digit (thumb)
pronator quadratus origin
distal quarter of anterior surface of ulna
pronator quadratus insertion
distal quarter of anterior surface of radius
pronator quadratus innervation
anterior interosseous nerve, from median nerve (C8, T1)
pronator quadratus action
pronates forearm; deep fibers bind radius and ulna together
brachioradialis origin
proximal two thirds of supra-epicondylar ridge of humerus
brachioradialis insertion
radial styloid process
brachioradialis innervation
radial nerve (C5, C6, C7)
brachioradialis action
relatively weak flexion of forearm; maximal when forearm is in midpronated position
extensor carpi radialis longus origin
lateral supra-epicondylar ridge of humerus
extensor carpi radialis longus insertion
dorsal base of 2nd metacarpal bone
extensor carpi radialis longus innervation
radial nerve (C6, C7)
extensor carpi radialis longus action
extend and abduct hand at wrist joint; active during fist clenching
extensor carpi radialis brevis origin
lateral epicondyle of humerus
extensor carpi radialis brevis insertion
dorsal aspect of base of 3rd metacarpal
extensor carpi radialis brevis innervation
deep branch of radial nerve (C7, C8)
extensor carpi radialis brevis action
extend and abduct hand at wrist joint; active during fist clenching
extensor digitorum origin
lateral epicondyle of humerus
extensor digitorum insertion
extensor expansions of medial 4 digits
extensor digitorum innervation
deep branch of radial nerve (C7, C8)
extensor digitorum action
extends medial four digits primarily at metacarpophalangeal joints, secondarily at interphalangeal joints
extensor digitorum minimi origin
lateral epicondyle of humerus
extensor digitorum minimi insertion
extensor expansion of 5th digit
extensor digitorum minimi innervation
deep branch of radial nerve (C7, C8)
extensor digitorum minimi action
extends 5th digit primarily at metacarpophalangeal joint, secondarily at interphalangeal joint
extensor carpi ulnaris origin
lateral epicondyle of humerus; posterior border of ulna via a shared aponeurosis
extensor carpi ulnaris insertion
dorsal aspect of base of 5th metacarpal
extensor carpi ulnaris innervation
deep branch of radial nerve (C7, C8)
extensor carpi ulnaris action
extends and adducts hand at wrist joint (also active during first clenching)
supinator origin
lateral epicondyle of humerus; radial collateral anular ligaments, supinator fossa; crest of ulna
supinator insertion
lateral, posterior, and anterior surfaces of proximal third of radius
supinator innervation
deep branch of radial nerve (C7, C8)
supinator action
supinates forearm, rotates radius to turn palm anteriorly or superiorly
extensor indicis origin
posterior surface of distal third of ulna and interosseous membrane
extensor indicis insertion
extensor expansion of 2nd digit
extensor indicis innervation
posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
extensor indicis action
extends 2nd digit (enabling its independent extension); helps extend hand at wrist
Abductor pollicis longus origin
middle one-third of the posterior surface of the radius and ulna; the interosseous membrane
Abductor pollicis longus insertion
base of 1st metacarpal
Abductor pollicis longus innervation
posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
Abductor pollicis longus action
abducts thumb and extends it at carpometacarpal joint
extensor pollicis longus origin
posterior surface of middle third of ulna and interosseous membrane
extensor pollicis longus insertion
dorsal aspect of base of distal phalanx of thumb
extensor pollicis longus innervation
posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
extensor pollicis longus action
extends distal phalanx of thumb at interphalangeal joint; extends metacarpophalangeal joint carpometacarpal joint
extensor pollicis brevis origin
posterior surface of distal third of radius and interosseous membrane
extensor pollicis brevis insertion
dorsal aspect of base of proximal phalanx of thumb
extensor pollicis brevis innervation
posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
extensor pollicis brevis action
extends proximal phalanx of thumb at metacarpophalangeal joint; extends carpometacarpal joint