Other information about the hand

Question 1

What are the slips that extensor digitorum divides into?

Answer 1

Central slip = inserts on base middle phalanx

2 lateral slips converge to insert onto base distal phalanx

Question 2

Where does flexor digitorum profundus insert?

Answer 2

Base distal phalanx of the 4 fingers

Question 3

Where does the flexor digitorum superficialis insert? What slips does it produce?

Answer 3

Base middle phalanx of 4 fingers
Divides to 2 slips @ proximal phalanx, FDP tendon through gap
Recombine to insert @ middle phalanx

Question 4

What is the deep and superficial border of the carpal tunnel? What passes through the carpal tunnel?

Answer 4

Deep = carpal bones
Superficial = flexor retinaculum (transverse carpal ligament)

Flex. pollicis longus tendon
Flex. digitorum superficialis (tendons to middle + ring pass superficial to index/little) + profundus tendons
Median nerve

Question 5

What are the attachments of the flexor retinaculum?

Answer 5

Lateral = scaphoid, trapezium
Medial = hook of hamate, pisiform

Question 6

What is Guyon’s canal?

Answer 6

Semi-rigid longitudinal canal in wrist, superficial to flexor retin.
For passage of ulnar artery + nerve
Roof = palmar carpal ligament

Question 7

What are the borders of the anatomical snuffbox?

Answer 7

LATERAL = tendons of abductor pollicis longus + ext. pollicis brevis
RADIAL = ext. pollicis longus tendon
PROXIMAL = styloid process of radius
FLOOR = scaphoid, trapezium
ROOF = skin

Question 8

What are the contents of the anatomical snuffbox?

Answer 8

Radial artery, superficial branch radial nerve, cephalic vein

Question 9

What do the ulnar and radial arteries divide into/converge to?

Answer 9

Superficial (mainly ulnar) + deep palmar (mainly radial = thumb + radial side index finger) arches

Question 10

What does the superficial palmar arch give off?

Answer 10

Common palmar digital arteries, supply fingers

Question 11

The ulnar nerve supplies all intrinsic hand muscles, except for…. which are supplied by the median nerve?

Answer 11

LOAF

Lumbricals (radial 2)
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis

Question 12

Due to overlap of cutaneous territories with peripheral nerves, what regions do you test for the peripheral nerves known to have a consistent supply?

Answer 12

RADIAL NERVE = dorsum of 1st webspace
MEDIAN NERVE = palmar surface tip of index finfer
ULNAR NERVE = ulnar border of hand