The hand

Question 1

What type of joint is the carpometacarpal joint (base of thumb)

Answer 1

synovial saddle joint
allows opposition of the thumb

Question 2

What type of joints are the metacarpophalangeal joints (MCPs)

Answer 2

synovial condyloid joints
allow flexion, extension, abduction, adduction, some circumduction

Question 3

What type of joints are the interphalangeals (PIP and DIPs)

Answer 3

synovial hinge

Question 4

Describe the function of the palmar aponeurosis

Answer 4

holds skin in place during movement
prevents loss of grip
protection of nerves and vessels in hand

Question 5

Describe the action and innervation of palmaris brevis

Answer 5

tightens palmar aponeurosis
innervated by ulnar nerve

Question 6

Where are the thenar and hypothenar eminences located

Answer 6

thenar - base of thumb
hypothenar - base of little finger

Question 7

Name the muscles of the thenar eminence

Answer 7

superficial - abductor policis brevis and flexor policis brevis
deep - opponens policis

Question 8

Innervation of the thenar eminence

Answer 8

recurrent branch of median nerve C8-T1

Question 9

Which intrinsic muscle of the thumb is not found in the thenar eminence

Answer 9

Adductor pollicis

Question 10

Describe the actions of adductor pollicis

Answer 10

adducts thumb @ CMCJ
flexion @ MCPJ

Question 11

Describe the innervation to adductor pollicis

Answer 11

Ulnar nerve C8-T1
this is due to its deep location

Question 12

Name the 3 muscles of the hypothenar eminence

Answer 12

abductor digiti minimi
flexor digiti minimi
opponens digiti minimi

Question 13

Describe the attachments and actions of abductor digiti minimi

Answer 13

pisiform to base of 5th proximal phalanx
action - abduction and flexion MCPJ little finger

Question 14

Describe the attachments and actions of flexor digiti minimi

Answer 14

hamate and flexor retinaculum
to
base of 5th proximal phalanx

flexion of MCPJ little finger

Question 15

Describe the attachments and actions of opponens digiti minimi

Answer 15

hamate and flexor retinaculum
to
5th metacarpal

weak opposition of little finger

Question 16

Describe the innervation to the hypothenar eminence

Answer 16

Deep branch of ulnar nerve C8-T1

Question 17

Describe the lumbricals of the hand

Answer 17

originate from tendons of FDP
insert onto dorsal expansion of fingers 2-5, crossing anterior surface of MCPJs as well as the posterior surface of the IP joints

Question 18

Describe the action of lumbricals

Answer 18

MCPJ flexion
IP Joint extension

Question 19

Describe the innervation of the lumbricals

Answer 19

lateral - median nerve C8-T1
medial - deep branch of ulnar nerve C8-T1

Question 20

Describe the innervation of the palmar interossei

Answer 20

deep branch of ulnar nerve

Question 21

Describe the action of the palmar interossei

Answer 21

adduction towards middle finger

Question 22

Describe the action of the dorsal interossei

Answer 22

Abduction - spreads fingers

Question 23

What is the largest artery to the thumb

Answer 23

Princeps pollicis artery - from radial artery

Question 24

Describe the general rules of innervation in the hand

Answer 24

lateral - median nerve
medial - ulnar nerve
thenar eminence - median nerve
hypothenar - ulnar nerve

Question 25

Describe the important dermatome landmarks

Answer 25

C5 - badge patch
C6 - pad of thumb
C7 - pad of middle finger
C8 - pad of little finger
T1 - medial side of elbow