Exam 2 Intrinsic Muscles of Hand Flashcards
What is the insertion of opponens pollicis?
Lateral side of 1st metacarpal
What is the origin of opponens pollicis?
Flexor retinaculum and tubercles of scaphoid and trapezium
What is the innervation of opponens pollicis?
Recurrent branch of median nerve C8, T1
What is the action of opponens pollicis?
To oppose thumb, it draws 1st metacarpal medially to center of palm and rotates it medially
What is the origin of abductor pollicis brevis?
Flexor retinaculum and tubercles of scaphoid and trapezium
What is the insertion of abductor pollicis brevis?
Lateral side of base of proximal phalanx of thumb
What is the innervation of abductor pollicis brevis?
Recurrent branch of median nerve C8, T1
What is the action of abductor pollicis brevis?
Abducts thumb, helps oppose it
What is the origin of flexor pollicis brevis?
Superficial and deep heads
Flexor retinaculum and tubercles of scaphoid and trapezium
What is the insertion of flexor pollicis brevis?
Lateral side of base of proximal phalanx of thumb
What is the innervation of flexor pollicis brevis?
Recurrent branch of median nerve C8, T1
What is the action of flexor pollicis brevis?
Flexes thumb
What is the origin of abductor digiti minimi?
pisiform
What is the insertion of abductor digiti minimi?
medial side of base of proximal phalanx of 5th finger
What is the innervation of abductor digiti minimi?
Deep branch of ulnar nerve C8, T1
What is the action of abductor digiti minimi?
Abducts 5th finger, assists in flexion of its proximal phalanx
What is the origin of flexor digiti minimi brevis?
Hook of hamate and flexor retinaculum
What is the insertion of flexor digiti minimi brevis?
Medial side of base of proximal phalanx of 5th finger
What is the innervation of flexor digiti minimi brevis?
Deep branch of ulnar nerve C8, T1
What is the action of flexor digiti minimi brevis?
Flexes proximal phalanx of 5th finger
What is the origin of opponens digiti minimi?
Hook of hamate and flexor retinaculum
What is the insertion of opponens digiti minimi?
medial border of 5th metacarpal
What is the innervation of opponens digiti minimi?
Deep branch of ulnar nerve C8, T1
What is the action of opponens digiti minimi?
Draws 5th metacarpal anterior and rotates it, bringing 5th finger into opposition with thumb
What is the origin of lumbricals?
1 and 2: lateral two tendons of flexor digitorum profundus
3 and 4: medial three tendons of flexor digitorum profundus
What is the insertion of lumbricals?
Lateral sides of extensor expansions of 2nd-5th fingers
What is the innervation of lumbricals?
Median nerve C8, T1
What is the action of lumbricals?
Flex metacarpophalangeal joints; extend interphalangeal joints of 2nd-5th fingers
What is the origin of dorsal interossei? 1-4
Adjacent sides of two metacarpals
What is the insertion of dorsal interossei 1-4?
Bases of proximal phalanges; extensor expansions of 2nd-4th fingers
What is the innervation of dorsal interossei 1-4?
deep branch of ulnar nerve C8, T1
What is the action of dorsal interossei 1-4?
abduct 2nd-4th fingers from axial line; act with lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints
What is the origin of palmar interossei 1-3?
Palmar surface of 2nd, 4th and 5th metacarpals
What is the insertion of palmar interossei 1-3?
Bases of proximal phalanges; extensor expansions of 2nd, 4th and 5h fingers
What is the innervation of palmar interossei 1-3?
Deep branch of ulnar nerve C8, T1
What is the action of palmar interosssei 1-3?
Adduct 2nd, 4th and 5th fingers toward axial line; assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints
What is the origin of adductor pollicus? 2
Oblique head: Bases of 2nd and 3rd metacarpals, capitate and adjacent carpals
Transverse head: anterior surface of shaft of 3rd metacarpal
What is the insertion if adductor pollicus?
Medial side of base of proximal phalanx of thumb
What is the innervation of adductor pollicus?
deep branch of ulnar nerve C8, T1
What is the action of adductor pollicus?
Adducts thumb toward lateral border of palm