muscles of the hand

Question 1

what are the three groups of the intrinsic hand muscles

Answer 1

thenar muscles: flexor pollicis brevis, abductor pollicis brevis and the opponents pollicis
hypothenar muscles:
flexor digiti minimi, abductor digiti minimi and the opponens digiti minimi
the others: adductor pollicis, lumbricals and the interossei - palmar and dorsal

Question 2

whats the proximal origin of the thenar and hypothenar muscle groups

Answer 2

the flexor retinaculum

Question 3

whats the attachmemts of the lumbricals and their function

Answer 3

proximally to the flexor digitorum profondus, distally to the extensor expansion as their tendon passes round radial side of fingers to get to the extensor hood. they thus do flexion at the metacarpophalangeal joint and extension at the interphalangeal at the same time

Question 4

why do the lumbricals do their movements at the same time

Answer 4

they do the flexion and extension at the same time due to their connection to the extensor hood. when the muscle contracts to flex the metacarpophalangeal, the connection to the extensor hood means it will extend the interphalangeal joints at the same time

Question 5

how many interossei are there

Answer 5

there are 4 dorsal and 3 palmar

Question 6

connections of the interossei and function

Answer 6

proximally to the metacarpal bones and distally to the extensor expansion Both interossei - Flexion at the
MCP & extension at IP
but the dorsal interossei abduct and the palmar interossei adduct

Question 7

why is there 4 dorsal interossei and 3 palmar

Answer 7

The abduction of the fingers is about the middle finger, it needs to stay in place. So there are two muscles on the middle finger then one on the side of every other finger.
Whereas palmar interossei has 3 muscles. As the finger is already in the middle, so no muscles are needed to adduct the middle finger.