Hand Anatomy

Question 1

what nerve are the extensor muscles inervated by?

Answer 1

the radial nerve

Question 2

what intrinsic muscles of the hand are inervated by the radial nerve?

Answer 2

none, in the hand the radial nerve provides sensation only

Question 3

Name the extensor tendons in the deep layer?

Answer 3

Extensor Policus Longus
Extensor Policus Brevis
Abductor policus Longus
Extensor Indicies

Question 4

Name the extensors in the superficial layer?

Answer 4

Extensor carpi Ulnaris*
Extensor Carpi Radialis Longus
Extensor Carpi Radialis Brevis 
Extensor digitorum *
Extensor Digiti Minimi *
(Brachiradialis) 
(Anconeus*)

Question 5

Which of the extensors have a common attachment site of the lateral epicondyle

Answer 5

Extensor carpi ulnaris
extensor digitorum
extensors digiti minimi
Anconeus

Question 6

Define Extrinsic muscles of the hand

Answer 6

located in the anterior and posterior compartments of the forearm. They control crude movements and produce a forceful grip.

Question 7

Define the intrinsic muscles of the hands

Answer 7

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

Question 8

Name the intrinsic muscles of the hand?

Answer 8

adductor pollicis
palmaris brevis
interossei
lumbricals
thenar and hypothenar muscle

Question 9

Name the thenar muscles

Answer 9

opponens pollicis
abductor policis brevis
Flexor policis brevis

Question 10

What is the attachment, inervation and action of the opponens policis

Answer 10

Attachment: Originates from the tubercle of the trapezium, and the associated flexor retinaculum. It inserts into the lateral margin of the metacarpal of the thumb

Innervation: Median Nerve

Action: opposes the thumb

Question 11

What is the attachment, inervation and action of the abductor policis brevis?

Answer 11

Attachment: Originates from the tubercles of the scaphoid and trapezium, and from the associated flexor retinaculum. Attaches to lateral side of proximal phalanx of the thumb.

Innervation: Median Nerve

Action: Abducts the thumb

Question 12

What is the attachment, enervation and action of the flexor policis brevis?

Answer 12

Attachment: Originates from the tubercle of the trapezium and from the associated flexor retinaculum. Attaches to the base of the proximal phalanx of the thumb.

Innervation: Median Nerve. The deep head is innervated by the ulnar nerve

Action: Flexes the metacarpophalangeal (MCP) joint of the thumb.

Question 13

What intrinsic muscles does the ulnar nerve innovate?

Answer 13

lumbricals (ring and little finger), hypothenar and interossei muscles

Question 14

What intirinsic muscles does the median nerve Innovate?

Answer 14

LOAF!

Lateral Lumbricals, Opponens Pollicis, Abductor Pollicis Brevis, Flexor Pollicis Brevis

Question 15

What is the attachment, innervation and action of the abductor digiti minimi?

Answer 15

Attachement: Originates from the pisiform and the tendon of the flexor carpi ulnaris. It attaches to the base of the proximal phalanx of the little finger.

Innervation: Ulnar Nerve

Action: Abducts the little finger

Question 16

What is the attachment, innervation and action of the flexor digiti minimi brevis

Answer 16

Attachment: Originates from the hook of hamate and adjacent flexor retinaculum, and inserts into the base of the proximal phalanx of the little finger.

Innervation: Ulnar Nerve

Action: Flexes MCP joint of little finger

Question 17

What are the lumbricles of the hand?

Answer 17

These 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

What is the attachment, innervation and action of the lumbricles?

Answer 18

Attachment: originate from the FDP and pass dorsally and laterally attaching to the extensor hood

Innervation:

Question 19

What is the attachment, innervation and action of the lumbricles?

Answer 19

Attachment: originate from the FDP and pass dorsally and laterally attaching to the extensor hood

Innervation:

• Lateral lumbricles (index and middle) = median nerve
• ring and little finger = ulnar nerve

Action : Flexion at the MCP joint and extension at the interphalangeal (IP) joints of each digit.

Question 20

what are the two groups of interossi muscles?

Answer 20

dorsal and palmer

Question 21

where are the interossi muscles found

Answer 21

in between the metacarpals

Question 22

what is the attachment, innervation and action of the interossi muscles? (Dorsal and palmar)

Answer 22

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

innervation: Ulnar nerve

Action: Abduct the fingers at the MCP joint.

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

Innervation: ulnar nerve

Action: adducts the fingers

Question 23

what is the palmaris brevis?

Answer 23

This is a small, thin muscle, found very superficially in the subcutaneous tissue of the hypothenar eminence.

Attachments: Originates from the palmar aponeurosis and flexor retinaculum, attaches to the dermis of the skin on the medial margin of the hand.

Actions: Wrinkles the skin of the hypothenar eminence and deepens the curvature of the hand, improving grip.

Innervation: Ulnar nerve.

Question 24

what is the adductor pollicis?

Answer 24

This is large triangular muscle with two heads. The radial artery passes anteriorly through the space between the two heads, forming the deep palmar arch.

Attachments: One head originates from metacarpal III. The other head originates from the capitate and adjacent areas of metacarpals II and III. Both attach into the base of the proximal phalanx of the thumb.

Actions: Adductor of the thumb.

Innervation: Ulnar nerve.

Question 25

what is the adductor pollicis?

Answer 25

This is large triangular muscle with two heads. The radial artery passes anteriorly through the space between the two heads, forming the deep palmar arch.

Attachments: One head originates from metacarpal III. The other head originates from the capitate and adjacent areas of metacarpals II and III. Both attach into the base of the proximal phalanx of the thumb.

Actions: Adductor of the thumb.

Innervation: Ulnar nerve.