Muscles of the hand Flashcards
What is the proximal attachment of the opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis?
Flexor retinaculum and tubercles of scaphoid and trapezium
What is the distal attachment of the opponens pollicis?
First metacarpal
What nerve innervates the opponens pollicis and abductor pollicis brevis?
Recurrent branch of median nerve (C8, T1)
What is the main action of the opponens pollicis?
- Oppose thumb
- draws first metacarpal medially to center of palm
What is the distal attachment of the abductor pollicis brevis and the flexor pollicis brevis?
Proximal phalanx of thumb
What is the main action of the abductor pollicis brevis?
-Abducts thumb and helps to oppose it
What is the main action of the flexor pollicis brevis?
-Flexes thumb
What is the proximal attachment of the adductor pollicis?
Oblique head: bases of 2nd and 3rd metacarpals, capitate, and adjacent carpals
Transverse head: shaft of 3rd metacarpal
What is the distal attachment of the adductor pollicis?
Proximal phalanx of thumb
What nerve innervates the flexor pollicis brevis?
Superficial head: recurrent branch of median nerve (C8,T1)
Deep head: Deep branch of ulnar nerve (C8, T1)
What nerve innervates the adductor pollicis?
Deep branch of ulnar nerve (C8, T1)
What is the main action of the adductor pollicis?
-Adducts thumb toward lateral border of palm
What is the proximal attachment of the abductor digiti minimi?
Pisiform
What is the distal attachment of the abductor digiti minimiand the flexor digiti minimi brevis?
Proximal phalanx of 5th digit
What nerve the abductor digiti minimi, flexor digiti minimi brevis, and the opponens digiti?
Deep branch of ulnar nerve (C8, T1)
What is the main action of the abductor digiti minimi?
- Abducts 5th digit
- Assists in flexion of its proximal phalanx
What is the proximal attachment of the flexor digiti minimi brevis and the opponens digiti?
Hook of hamate and flexor retinaculum
What is the main action of the flexor digiti minimi brevis?
-Flexes proximal phalanx of 5th digit
What is the distal attachment of the opponens digiti?
5th metacarpal
What is the main action of the opponens digiti?
-Draws 5th metacarpal anterior and rotates it, bringing 5th digit into opposition with thumb
What is the proximal attachment of the 1st and 2nd lumbricals?
Lateral two tendons of flexor digitorum profundus (as unipennate muscles)
What is the distal attachment of the 1st-4th lumbricles?
Lateral sides of extensor expansions of 2nd-5th digits
What nerve innervates the 1st and 2nd lumbricles?
Median nerve (C8, T1)
What is the main action of the 1st-4th lumbricles?
- Flex metacarpophalangeal joints
- extends interphalangeal joints of 2nd-5th digits
What is the proximal attachment of the 3rd and 4th lumbricles?
Medial three tendons of flexor digitorum profundus (as bipennate muscles)
What nerve innervates the 3rd and 4th lumbricles?
Deep branch of ulnar nerve (C8,T1)
What is the proximal attachment of the dorsal interossei 1st-4th?
Adjacent sides of two metacarpals (as bipennate muscles)
What is the distal attachment of the dorsal interossei?
Proximal phalanges; extensor expansions of 2nd-4th digits
What nerve innervates the dorsal interossei and the palmar interossei?
Deep branch of ulnar nerve (C8, T1)
What is the main action of the dorsal interossei?
- Abduct 2nd-4th digits from axial line
- helps flex metacarpophalangeal joints and extends interphalangeal joints
What is the proximal attachment of the palmar interossei 1st-3rd?
Palmar surfaces of 2nd, 4th, and 5th metacarpals (as unipennate muscles)
What is the distal attachment of the palmar interossei?
Proximal phalanges and extensor expansions of 2nd, 4th, and 5th digits
What is the main action of the palmar interossei?
-Adducts 2nd, 4th, and 5th digits toward axial line
