Hand

Question 1

What are the three bone types in the hand? How many are there?

Answer 1

1. Carpals (SLTPTTCH) = 8
2. Metacarpals (one for each finger/thumb) = 5
3. Phalanges (three for each finger, two for thumb) = 14

Question 2

Name the joints

Answer 2

Question 3

Caropmetacarpal joint - location and function

Answer 3

between the carpal and metacarpal bones, saddle shape at the thumb joint increases flexibility

Question 4

Metacarpophalangeal (MP) joint: location and function(s)

Answer 4

• Between metacarpal and phalanges
• Flexion/extension/abduction: All digits
• Oppose/Repose: Digits 1 and 5
• Adduction: All digits, except digit 3 (middle finger)

Question 5

Proximal interphalangeal (PIP) joint: function

Answer 5

flexion and extension only

Question 6

Distal interphalangeal joint (DIP): function

Answer 6

flexion and extension only

Question 7

Carpal tunnel

1. Nerves
2. Muscles
3. Arteries

Answer 7

1. Median nerve only
2. Flexor digitorum superficialis (FDS), Flexor digitorum profundus (FDP), Flexor pollicis longus (FPL), Flexor carpi radialis (FCR) –> 4 tendons
3. NONE

Question 8

Movements of the fingers

Answer 8

Question 9

Movements of the thumb

Answer 9

Question 10

What are the groups of intrinsic hand muscles?

Answer 10

4 groups

1. Thumb muscles
2. Little Finger Muscles
3. Interosseous muscles
4. Lumbrical muscles

Question 11

What are the thumb muscles? What is the innervation of each?

Answer 11

Mnemonic: :FABO”

1. flexor pollicis brevis (thenar muscle = recurrent branch of medial nerve)
2. abductor pollicis brevis (thenar muscle = recurrent branch of medial nerve)
3. opponens pollicis brevis (thenar muscle = recurrent branch of medial nerve)
4. adductor pollicis (deep branch of ulnar nerve)

Question 12

What are the little finger muscles? Innervations of each?

Answer 12

“FABO”

1. Flexor digiti minimi brevis (hypothenar muscle = deep branch of ulnar nerve)
2. Abductor digiti minimi (hypothenar muscle = deep branch of ulnar nerve)
3. Opponens digiti minimi (hypothenar muscle = deep branch of ulnar nerve)

Question 13

Interosseous muscles: where are they, functon, and two types

Answer 13

1. between metacarpals
2. abduction and adduction of the fingers (in reference to the middle finger)
3. Palmar interossei and dorsal interossei

Question 14

Palmar interossei

What does it do, where is it, what innervates it.

Answer 14

1. Adducts the digits (“PAD”)
2. Present in all fingers, except middle (No adduction for middle) = three total
3. Deep branch of the ulnar nerve

Question 15

Dorsal interossei

What does it do, where is it, what innervates it.

Answer 15

1. Abducts the digits (DAB)
2. 2 in the middle, 1 in index and ring fingers (4 total)
3. Deep branch of the ulnar nerve

Question 16

Lumbricals: OINA

Answer 16

1. Origin: Flexor digitorum profundas (FDP)
2. Insertion: Extensor expansion
3. Innervation: Lateral 2 lumbricals= median nerve, Medial 2 lumbricals= deep ulnar nerve
4. Action: Flex the MP joints + Extend the IP joints (Form the L-shape for writing, “L-shape for lumbrical”)

Question 17

Draw the pathway of the MC nerve.

Question 18

Draw the pathway of the radial nerve.

Question 19

Draw the pathway of the median nerve.

Question 20

Draw the pathway of the ulnar nerve.

Question 21

Draw the pathway of the brachial artery (major artery of the arm).

Question 22

Draw the pathway of the superficial veins.

Question 23

What are the dermatomes of the hand?

Answer 23

C6: Thumb

C7: index and middle finger

C8: ring and little finger

Question 24

Define terms:

1. Palmar metacarpal arteries
2. Vena comitantes
3. Perforating veins

Answer 24

1. Connect the deep arch to the common digital arteries (of the superficial arch)
2. Deep veins that follow arteries (brachial vein with brachial artery)
3. Deep vein that connects deep and superficial veins

Question 25

Synovial sheathes - function, types, where is it continuous?

Answer 25

1. Allow tendons to move freely
2. Common flexor sheath - tendons in the carpal tunnel
3. Fibrous digital sheath - surround each digits to prevent bowstringing (tendons coming off bones)
4. Digital sheath of the pinky continuous with the common flexor sheath => infections can spread

Question 26

Extensor Expansion/Hood: Function, Bands, and what inserts on it

Answer 26

1. dorsal aponeurosis holds tendons in place
2. Central band inserts on middle phalanx, Lateral bands converge on distal phalanx
3. Extensor digitorum insert on the central band, Lumbricals and Interosseous muscles insert on the lateral band

Question 27

Which bone moves during supination and pronation?

Answer 27

The radius (all muscles that cause supination/pronation MUST insert on the radius)

Supination: biceps brachii and supinator

Pronater; Pronater Teres

Question 28

Which nerves have no branches in the arm?

Answer 28

Median and ulnar

Question 29

What is innervated by the deep ulnar nerve?

Answer 29

1. Hypothenar muscles
2. Interosseus muscles
3. Medial two lumbricals
4. Adductor pollicis (Non-thenar muscle)

Question 30

What is innervated by the MC nerve?

Answer 30

Only three muscles

1. Coracobrachialis (pierces)
2. Biceps brachii (passes under)
3. Brachialis (passes over)

Question 31

What are the lumbricals innervated by?

Answer 31

Deep ulnar nerve (medial two digits)

AND proper palmar digital branch of the median nerve (lateral two digits)

Question 32

1. Major arterial blood supply to the thumb?
2. Major blood supply to the digits 2-5?
3. Where does the superficial arch receive blood?

Answer 32

1. Princeps pollicis artery (end of radial artery)
2. Superficial palmar arch (from ulnar artery)
3. Both ulnar and radial arteries