Muscles of the hand

Question 1

Extrinsic muscles of the hand

Answer 1

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

Question 2

Intrinsic muscles of the hand

Answer 2

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

Question 3

What are the thenar muscles?

Answer 3

Opponens Pollicis, Abductor Pollicis Brevis, Flexor Pollicis Brevis

Question 4

What are the thenar muscles responsible for?

Answer 4

Fine movements of the thumb

Question 5

Innervation of the thenar muscles

Answer 5

Median nerve

Question 6

Opponens pollicis actions

Answer 6

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

Question 7

Opponens pollicis innervation

Answer 7

Median nerve

Question 8

Abductor pollicis brevis actions

Answer 8

Abducts the thumb

Question 9

Abductor pollicis brevis innervation

Answer 9

Median nerve

Question 10

Flexor pollicis brevis actions

Answer 10

Flexes the metacarpophalangeal (MCP) joint of the thumb.

Question 11

Flexor pollicis brevis innervation

Answer 11

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

Question 12

What are the hypothenar muscles of the hand?

Answer 12

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

Question 13

Innervation of the hypothenar muscles

Answer 13

Ulnar nerve

Question 14

Opponens Digiti Minimi actions

Answer 14

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

Question 15

Abductor Digiti Minimi actions

Answer 15

Abducts the little finger.

Question 16

Flexor Digiti Minimi Brevis actions

Answer 16

Flexes the MCP joint of the little finger.

Question 17

Lumbricals

Answer 17

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.

Question 18

Denervation of the lumbricals leads to:

Answer 18

Ulnar claw and hand of benediction

Question 19

Lumbrical attachments

Answer 19

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.

Question 20

Lumbrical actions

Answer 20

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

Question 21

Lumbricals innervation

Answer 21

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.

Question 22

Dorsal interossei attachments

Answer 22

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

Question 23

Dorsal interossei actions

Answer 23

Abduct the fingers at the MCP joint

Question 24

Dorsal interossei innnervation

Answer 24

Ulnar nerve

Question 25

Palmar interossei attachments

Answer 25

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

Question 26

Palmar interossei actions

Answer 26

Adducts the fingers at the MCP joint.

Question 27

Palmar interossei innervation

Answer 27

Ulnar nerve