Wrist and hand anatomy

Question 1

What forms the roof of the anatomical snuffbox?

Answer 1

Skin

Question 2

What forms the floor of the anatomical snuffbox?

Answer 2

Scaphoid and trapezium.

Question 3

What forms the proximal border of the anatomical snuffbox?

Answer 3

Styloid process of radius

Question 4

What forms the radial border of the anatomical snuffbox?

Answer 4

Tendons of the extensor pollicis brevis and abductor pollicis longus

Question 5

What forms the ulnar border of the anatomical snuffbox?

Answer 5

Tendon of the extensor pollicis longus

Question 6

What is included in the contents of the anatomical snuff box?

Answer 6

Radial artery
Superficial branch of radial nerve
Cephalic vein

Question 7

Pain and tenderness in the anatomical snuffbox suggests what?

Answer 7

Scaphoid fracture

Question 8

What is the scaphoid bone at risk of when fractured?

Answer 8

Avascular necrosis

Question 9

Why is the scaphoid bone at risk of avascular necrosis when fractured?

Answer 9

Due to retrograde blood supply that enters at the distal end

Question 10

Fractures of which aspect of the scaphoid are most at risk of causing avascular necrosis?

Answer 10

Fractures to the middle/ ‘waist’ if the scaphoid.

Question 11

What is the extensor retinaculum?

Answer 11

A thickened, fibrous band that holds the extensor tendons at the dorsum of the wrist.

Question 12

What is De Quervain’s tenosynovitis?

Answer 12

Inflammation of the tendons in the first extensor compartment of the wrist.

Question 13

What are the attachments of the extensor retinaculum of the wrist?

Answer 13

Lateral surface of distal radius proximally and pisoform + traquetal bones distally.

Question 14

What type of joint is the wrist?

Answer 14

Ellipsoidal (condyloid) type synovial joint.

Question 15

Which muscles allow for flexion of the wrist?

Answer 15

Flexor carpi ulnas
Flexor carpi radialis
Flexor digitorum superficialis (assistance)

Question 16

Which muscles allow for extension of the wrist?

Answer 16

Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris
Extensor digitorum (assistance)

Question 17

Which muscles allow for adduction at the wrist?

Answer 17

Extensor carpi ulnaris
Flexor carpi ulnaris

Question 18

Which muscles allow for abduction at the wrist?

Answer 18

Abductor pollicis longus
Flexor carpi radials
Extensor carpi radialis longus
Extensor carpi radialis brevis

Question 19

What structures form the carpal tunnel?

Answer 19

Flexor retinaciulum superficially
Carpal bones posteriorly
Scaphoid and trapezium laterally
Hook of the hamate and pisiform medially

Question 20

Where does the flexor retinaculum span between?

Answer 20

Hook of hamate and pisiform + scaphoid and trapezius

Question 21

What does the carpal tunnel contain?

Answer 21

9 tendons surrounded by synovial sheaths and the median nerve

Question 22

What aspect of the median nerve is not found within the carpal tunnel?

Answer 22

Palmar cutaneous branch (is given off prior to median nerve entering carpal tunnel)

Question 23

Where does the palmar cutaneous branch of the median nerve travel with regards to the flexor retinaculum?

Answer 23

Superficially to it.

Question 24

Which tendons are found in the carpal tunnel?

Answer 24

Tendon of flexor pollicis longus
4 tendons of flexor digitorum profundus
4 tendons of flexor digitorum superficialis

Question 25

Which tendon is located within the flexor retinaculum?

Answer 25

Flexor carpi radialis tendon

Question 26

Which muscles make up the thenar eminence?

Answer 26

Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis

Question 27

What are the thenar muscles responsible for?

Answer 27

Fine movements of the thumb

Question 28

Which nerve innervates the muscles of the thenar eminence?

Answer 28

Median nerve (recurrent branch)

Question 29

What is the function of the opponent pollicis?

Answer 29

Opposition of the thumb (medially rotates and flexes the metacarpal on the trapezium)

Question 30

What is the function of the abductor pollicis brevis?

Answer 30

Abducts the thumb.

Question 31

What is the function of the flexor pollicis brevis?

Answer 31

Flexes the MCP joint of the thumb.

Question 32

What are the muscle components of the hypothenar eminence?

Answer 32

Opponens digiti minimi Abductor digiti minimi Flexor digiti minimi brevis

Question 33

What is the innervation of muscles in the hypothenar eminence?

Answer 33

Ulnar nerve

Question 34

What is the function of the opponents digiti minimi?

Answer 34

Opposition of little finger

Question 35

What is the function of the abductor digiti minimi?

Answer 35

Abducts the little finger

Question 36

What is the function of the flexor digiti minimi?

Answer 36

Flexes MCP joint of little finger

Question 37

What structures do the lumbricals link together?

Answer 37

The extensor tendons and flexor tendons.

Question 38

What are the functions of the lumbricals?

Answer 38

Flexion at the MCP joints Extension at IP joints

Question 39

What is the innervation of the lumbricals?

Answer 39

Lateral 2 lumbricals = median nerve Medial 2 lumbricals = ulnar nerve

Question 40

Where are the interoessei located?

Answer 40

Between metacarpal bones of the hand (there are dorsal and palmar groups)

Question 41

What is a common function of the interossei?

Answer 41

Assist lumbricals in flexion of MCP joints and extension of IP joints.

Question 42

What is the function of the dorsal interossei?

Answer 42

Finger abduction

Question 43

What is the function of the palmar interossei?

Answer 43

Finger adduction

Question 44

What is the innervation of the interossei?

Answer 44

Ulnar nerve

Question 45

Which 2 muscles of the hand do not fit into a common group?

Answer 45

Palmaris brevis Adductor pollicis

Question 46

What is the innervation of the palmaris brevis?

Answer 46

Ulnar nerve

Question 47

What is the innervation of the adductor pollicis?

Answer 47

Ulnar nerve

Question 48

What is the function of the palmaris brevis?

Answer 48

Wrinkles the skin of the hypothenar eminence + deepens the curvature of the hand (improves grip)

Question 49

What is the function of the adductor pollicis?

Answer 49

Adducts the thumb

Question 50

Where do the lumbricals originate from?

Answer 50

A tendon of the flexor digirotum profundus

Question 51

Where do the lumbricals insert to?

Answer 51

Pass dorsally and laterally around each finger and insert into the extensor hood.

Question 52

What is the function of the flexor pulley system of the hand?

Answer 52

To hold the flexor tendons against the phalanges, preventing them from pulling away and bowstringing.

Question 53

Where do the tendons of the flexor digitorum superficialis attach to?

Answer 53

The base of the middle phalanx.

Question 54

Where do the tendons of the flexor digitorum profundus attach to?

Answer 54

The base of the distal phalanx.

Question 55

Which tendons of the hand flex the IP joints?

Answer 55

Flexor digitorum profundus and the flexor digitorum superficialis

Question 56

Which tendons of the hand flex the DIP joints?

Answer 56

Flexor digitorum profundus.

Question 57

The flexor retinaculum is attached medially to which carpal bones?

Answer 57

Hamate and pisiform

Question 58

What are the lateral attachments of the flexor retinaculum?

Answer 58

Scaphoid and trapezium

Question 59

What is the function of the palmar interossei?

Answer 59

Adduct the fingers towards middle finger