Muscles of the hand Flashcards
Name the thenar muscles.
Abductor pollicis brevi
Flexor pollicis brevi
Opponens pollicis
Name the hypothenar muscles.
Abductor digiti minimi
Flexor digiti minimi
Opponens digiti minimi
How many lumbrical muscles are there?
4 - one for each finger
Which brachial plexus nerves supply the hand?
Median and Ulnar
What is the difference between intrinsic and extrinsic muscles?
Extrinsic - located in anterior and posterior compartments of forearm. Control crude movements and strong grip.
Intrinsic are in hand itself. Control fine movements
Where are the interossei muscles located? Into which groups are they divided?
Between the metacarpals.
Dorsal and palmar interossei.
Where are the dorsal interossei located?
Dorsum of hand (back of hand)
How many dorsal interossei are there?
4
Where are the palmar interossei located?
Anteriorly on the hand.
How many palmar interossei are there?
3
What do the dorsal interossei do?
Abduct fingers
Flexes Metacarpophalangeal joint
Extends proximal and distal interphalangeal joints
What do the palmar interossei do?
Flexes Metacarpophalangeal joint 2,4,5
Extends proximal and distal interphalangeal joints 2,4,5
Why don’t the palmar interossei move the 3rd finger?
There’s no palmar interossei there!
What action do the lumbricals do?
Flexes Metacarpophalangeal joints
Extends proximal and distal interphalangeal joints
What action does the flexor pollicis brevis do?
Flexes Metacarpophalangeal joint on thumb
and Carpometacarpal joint of thumb
What action does the abductor pollicis brevis do?
Abducts carpometacarpal joint of thumb
What action does the Opponens pollicis do?
Medially rotates thumb
Opposable thumb!
What action does the flexor digiti minimi do?
Flexes 5th finger
and 5th Metacarpophalangeal joint
What action does the abductor digiti minimi do?
Flexes 5th finger
What action does the Opponens digiti minimi do?
Laterally rotates 5th finger
to meet thumb!
