Hand - intrinsic muscles Flashcards
which nerve innervates the thenar muscles?
median
what digit do the thenars act upon?
thumb (first digit)
name the 3 thenar muscles
oppenens pollicis
abductor pollicis brevis
flexor pollicis brevis
how many thenar muscles are there?
3
what is the action of oppenens pollicis?
opposes thumb - by rotating and flexing the metacarpal on the trapezium
what is the action of abductor pollicis brevis?
abducts thumb
what is the action of flexor pollicis brevis?
flexes MCP joint of thumb
which nerve innervates the hypothenars?
ulnar
which digit do the hypothenars act upon?
little finger - digit V
how many hypothenars are there?
3
name the 3 hypothenars
opponens digiti minimi
abductor digiti minimi
flexor digiti minimi brevis
what is the action of opponens digiti minimi?
opposition of little finger - rotates metacarpal V towards palm
what is the action of abductor digiti minimi?
abducts little finger
what is the action of flexor digiti minimi brevis?
flexes little finger at MCP
what is an important function of the lumbricals?
link the flexor and extensor tendons
how many lumbricals are there in the hand?
4
where do the lumbricals of the hand insert?
extensor hood of each digit
what is the action of the lumbricals?
flex at MCP and extend at IP
describe the innervation of the lumbricals of the hand
medial two digits = ulnar nerve
lateral two digits = median nerve
what is the general action of the interossei?
assist lumbricals in flexion at MCP and extension at IP
how many dorsal interossei are there?
4
how many palmar interossei are there?
3
what is the action of the dorsal interossei?
abduct fingers at MCP joint
what is the action of the palmar interossei?
adduct fingers at MCP joints
