Intrinsic Muscles of the Hand Flashcards
Which muscles make up the thenar muscles?
- Abductor pollicis brevis
- Flexor pollicis brevis
- Oppenens pollicis
Name the intrinsic muscles of the hand?
- Thenar muscles
- Adductor pollicis
- Hypothenar muscles
- “Short” muscles of the hand
Main action of the abductor pollicis brevis?
Abducts thumb; helps to oppose thumb
Main action of the flexor pollicis brevis?
Flexes thumb
Main action of the oppenens pollicis?
Laterally opposes & medially rotates thumb
Innervation of thenar muscles?
Median nerve
Proximal attachment of thenar muscles?
- Flexor retinaculum
- Tubercles of scaphoid & trapezium
Distal attachment of abductor pollicis muscle?
Lat. side of base of prox. thumb phalanx
Distal attachment of flexor pollicis brevis?
Lat. side of base of prox. thumb phalanx
Distal attachment of opponens pollicis?
Lat. side of 1st metacarpal
Main action of adductor pollicis?
Adducts thumb towards middle digit
Innervation of adductor pollicis?
Ulnar nerve
Proximal attachment of adductor pollicis?
- Oblique head:
- Base of 2nd & 3rd metacarpal
- Capitate
- Adjacent carpals - Transverse head:
- Ant. surface of body of 3rd metacarpal
Distal attachment of adductor pollicis?
Med. side of base of proximal phalanx of thumb
Which muscles make up the hypothenar muscles?
- Abductor digiti minimi
- Flexor digiti minimi
- Opponens digiti minimi
Main action of the abductor digiti minimi?
Abducts 5th digits
Main action of the flexor digiti minimi?
Flexes proximal phalanx of 5th digit
Main action of the opponens digiti mini?
Draws 5th digit anteriorly & rotates it
Innervation of hypothenar muscles?
Ulnar nerve
Proximal attachment of the abductor digiti minimi?
Pisiform
Distal attachment of abductor digiti minimi?
Med. side of base of proximal phalanx of digiti minimi
Proximal attachment of the flexor digiti minimi?
Flexor retinaculum & hook of hamate
Distal attachment of the flexor digiti minimi?
Med. side of proximal phalanx of digiti minimi
Proximal attachment of the opponens digiti minimi?
Flexor retinaculum & hook of hamate
Distal attachment of the opponens digiti minimi?
Med. border of 5th metacarpal
Which muscles make up the “short” muscles of the hand?
- Lumbricals
- Dorsal interossei (1-4)
- Palmar interossei (1-3)
Main action of the lumbricals?
- Flex digits at metacarpophalangeal joints
- Extends interphalangeal joints
Main action of the dorsal interossei muscles?
Abducts digits from axial line
Main action of the palmar interossei muscles?
Adducts digits towards axial line
Innervation of lumbricals?
1-2: median nerve
3-4: ulnar nerve
Innervation of dorsal and palmar interossei?
Ulnar nerve
Proximal attachment of the lumbricals?
- 1 & 2: lateral tendons of flexor digitorum profundus
- 3 & 4: medial 2 tendons of flexor digitorum profundus
Distal attachment of lumbricals?
Lat. side of extensor expansion of digitis 2-5
Proximal attachment of the dorsal interossei?
Adjacent sides of 2 metacarpals
Distal attachment of dorsal interossei?
Lat. sides of extensor expansions of digits 2-5
Proximal attachment of the palmar interossei?
Palmar surface of 2nd, 4th & 5th metacarpals
Distal attachment of palmar interossei?
Extensor expansions & bases of proximal phlanges of digits 2, 4 & 5