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Flashcards in Muscles of the hand Deck (27)
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1

Extrinsic muscles of the hand

Located in the anterior and posterior compartments of the forearm. They control crude movement and produce a strong grip.

2

Intrinsic muscles of the hand

Located within the hand itself. They are responsible for he fine motor functions of the hand.

3

What are the thenar muscles?

Opponens Pollicis, Abductor Pollicis Brevis, Flexor Pollicis Brevis

4

What are the thenar muscles responsible for?

Fine movements of the thumb

5

Innervation of the thenar muscles

Median nerve

6

Opponens pollicis actions

Opposes the thumb, by medially rotating and flexing the metacarpal on the trapezium

7

Opponens pollicis innervation

Median nerve

8

Abductor pollicis brevis actions

Abducts the thumb

9

Abductor pollicis brevis innervation

Median nerve

10

Flexor pollicis brevis actions

Flexes the metacarpophalangeal (MCP) joint of the thumb.

11

Flexor pollicis brevis innervation

Median nerve. The deep head is innervated by the deep branch of the ulnar nerve.

12

What are the hypothenar muscles of the hand?

Opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis

13

Innervation of the hypothenar muscles

Ulnar nerve

14

Opponens Digiti Minimi actions

It rotates the metacarpal of the little finger towards the palm, producing opposition.

15

Abductor Digiti Minimi actions

Abducts the little finger.

16

Flexor Digiti Minimi Brevis actions

Flexes the MCP joint of the little finger.

17

Lumbricals

There are four lumbricals in the hand, each associated with a finger. They are very crucial to finger movement, linking the extensor tendons to the flexor tendons.

18

Denervation of the lumbricals leads to:

Ulnar claw and hand of benediction

19

Lumbrical attachments

Each lumbrical originates from a tendon of the flexor digitorum profundus. They pass dorsally and laterally around each finger, and inserts into the extensor hood.

20

Lumbrical actions

The flex at the MCP joint, and extend at the interphalangeal (IP) joints of each finger.

21

Lumbricals innervation

The lateral two lumbricals (of the index and middle fingers) are innervated by the median nerve. The medial two lumbricals (of the little and ring fingers) are innervated by the ulnar nerve.

22

Dorsal interossei attachments

Each interossei originates from the lateral and medial surfaces of the metacarpals. They attach into the extensor hood and proximal phalanx of each finger.

23

Dorsal interossei actions

Abduct the fingers at the MCP joint

24

Dorsal interossei innnervation

Ulnar nerve

25

Palmar interossei attachments

Each interossei originates from a medial or lateral surface of a metacarpal, and attaches into the extensor hood and proximal phalanx of same finger.

26

Palmar interossei actions

Adducts the fingers at the MCP joint.

27

Palmar interossei innervation

Ulnar nerve