Week 5: The Hand

Question 1

What types of joints are the small joints of the hand?

Answer 1

synovial

Question 2

What happens when you flex the MCP, PIP and DIP joints?

Answer 2

makes a fist

Question 3

Which two groups of muscles allow movement of the fingers and thumbs?

Answer 3

1. Extrinsic muscles: muscles in the anterior and posterior forearm whose tendons travel down into the hand
2. Intrinsic muscles: muscles located in the hand

Question 4

There are 4 groups of intrinsic hand muscles and 1 single muscle. What are they?

Answer 4

1. The Thenar Eminence
2. The hypothenar eminence
3. The lumbrical muscles
4. The interosseous muscles (interossei)

Single muscles: adductor pollicis

Question 5

What is the thenar eminance?

Answer 5

• group of 3 muscles
• lie in the palm below the thumb
• move the thumb

Question 6

What is the hypothenar eminence?

Answer 6

• group of 3 muscles
• lie in the palm below the little finger
• move the little finger

Question 7

How many lumbrical muscles do we have?

Answer 7

4 - each one is attached to an FDP tendon

Question 8

What is the interosseous muscles (interossei)?

Answer 8

• muscles that lie between adjacent metacarpals

- there are 3 in the palm and 4 in the dorsum

Question 9

What is the adductor pollicis?

Answer 9

a single muscle that lies in the palm and adducts the thumb

Question 10

Which intrinsic muscles does the ulnar nerve innervate?

Answer 10

• the hypothenar eminence muscles
• all the interossei
• the medial 2 lumbrical muscles (to the 4th and 5th digits)
• adductor pollicis

Question 11

Which intrinsic muscles does the median nerve innervate?

Answer 11

• thenar eminence muscles

- lateral 2 lumbricals

Question 12

Which 3 muscles make up the thenar eminence and what are their functions?

Answer 12

1. Abductor pollicis brevis - abductor
2. Flexor pollicis brevis - flexor
3. Opponens pollicis (deeper) - opposer

Question 13

Where do the thenar eminence muscles originate

Answer 13

carpal bones

Question 14

Where does each thenar eminance muscle insert

Answer 14

1. APB = base of proximal phalanx of thumb
2. FPB = base of proximal phalanx of thumb
3. OP = 1st metacarpal

Question 15

How does the OP lie in relation to the APB?

Answer 15

Deep

Question 16

Which nerve innervates the thenar eminence?

Answer 16

recurrent branch of the median nerve

Question 17

What are the 3 muscles in the hypothenar eminence?

Answer 17

1. Abductor digiti minimi
2. Flexor digiti minimi
3. Opponens digiti minimi (deeper)

Question 18

Where do the hypothenar eminence muscles originate?

Answer 18

carpal bones (centred on the hamate and pisiform)

Question 19

Where do the hypothenar eminence muscles insert?

Answer 19

1. ADM and FDM = base of the proximal phalanx of the 5th digit
2. ODM = 5th metacarpal

Question 20

Which nerve innervates the hypothenar eminence?

Answer 20

deep branch of the ulnar nerve

Question 21

Where does the adductor pollicis originate?

Answer 21

3rd metacarpal and capitate

Question 22

Where does the adductor pollicis insert?

Answer 22

base of the proximal phalanx of thumb

Question 23

What is the function of the adductor pollicis?

Answer 23

adducts the thumb

Question 24

What nerve is the adductor pollicis innervated by

Answer 24

deep branch of the ulnar

Question 25

Where do the lumbrical muscles originate?

Answer 25

tendons of FDP

Question 26

Where do the lumbrical muscles insert?

Answer 26

base of proximal phalanges and extensor expansion

Question 27

What is the action of the lumbrical muscles?

Answer 27

- MCJP flexion | - PIPJ and DIPJ extension

Question 28

Which nerves innervate the lumbrical muscles?

Answer 28

medial 2 = ulnar nerve lateral 2 = median nerve innervated by the same nerve as their parent FDP

Question 29

where do the palmar interossei originate?

Answer 29

metacarpals

Question 30

Where do the palmar interossei insert?

Answer 30

base of proximal phalanges and extensor expansionn

Question 31

What is the action of the palmar interossei?

Answer 31

- adducts fingers | - contribute to flexion at MCJPs and extension at the PIPJs and DIPJs via their insertion onto the extensor expansion

Question 32

Which nerve innervates the palmar interossei?

Answer 32

deep branch of ulnar nerve

Question 33

How many palmar interossei are there?

Answer 33

3

Question 34

Where do the dorsal interossei originate?

Answer 34

metacarpals

Question 35

Where do the dorsal interossei insert?

Answer 35

base of proximal phalanges and extensor expansion

Question 36

What is the action of the dorsal interossei?

Answer 36

- abduct fingers - contribute to flexion at the MCPJs and extension at the PIPJs and DIPJs via their insertion onto the extensor expansion

Question 37

Which nerve innervates the dorsal interossei?

Answer 37

deep branch of ulnar nerve

Question 38

The radial and ulnar arteries anastomose in the palm to form what?

Answer 38

palmar arches

Question 39

What arises from the palmar arch?

Answer 39

metacarpal and digit arteries

Question 40

Which carpal bone is most commonly dislocated?

Answer 40

lunate

Question 41

What is meant by a 'claw hand'?

Answer 41

- describes a hand after injury to the ulnar nerve - hyperextension of MCP joints of the 4th and 5th digits - flexion at PIP and DIP joints of 4th and 5th

Question 42

what are the possible movements of the fingers?

Answer 42

flexion, extension, abduction and adduction

Question 43

Which joints are predominately affected in osteoarthritis?

Answer 43

proximal and distal interphalangeal joints

Question 44

Which joints are characteristically affected in rheumatoid arthritis?

Answer 44

metacarpals

Question 45

Where do the palmar interossei lie in relation to lumbricals and FDP?

Answer 45

Deep to

Question 46

Where does the 1st dorsal interossei lie?

Answer 46

in the web space between the thumb and the 1st digit

Question 47

What is the Allens test?

Answer 47

- arterial blood gas at the radial artery - Occlude arteries and squeeze hand - hand will turn whiter - Release one finger on the radial side and hand will turn red - radial artery repurfuses - Release one finger on the ulnar side and hand will turn red - ulnar artery reperfuses