1Kaan Yücel M.D., Ph.D 27.March.2014 Thursday

ANATOMY OF THE HAND

IN 14 QUESTIONS

2

1. ...bones of the hand ?

3

2. What are flexor retinaculum & carpal tunnel?The carpal tunnel formed anteriorly at wrist by a deep arch formed bycarpal bones & flexor retinaculum (transverse carpal ligament)

Flexor digitorum superficialisFlexor digitorum profundusFlexor pollicis longus Median nerve

Pass through the carpal tunnel

4

2. What are flexor retinaculum & carpal tunnel?The carpal tunnel formed anteriorly at wrist by a deep arch formed bycarpal bones & flexor retinaculum (transverse carpal ligament)

Flexor digitorum superficialisFlexor digitorum profundusFlexor pollicis longus Median nerve (anterior to tendons)

Pass through the carpal tunnel

5

2. What are flexor retinaculum & carpal tunnel?The carpal tunnel formed anteriorly at wrist by a deep arch formed bycarpal bones & flexor retinaculum (transverse carpal ligament)

Flexor digitorum superficialisFlexor digitorum profundusFlexor pollicis longus Median nerve (anterior to tendons)Pass through the carpal tunnel

6

BONES OF THE HAND

Carpal arch The carpal bones do not lie in a flat plane; rather, they form an arch, whose base is directed anteriorly.

lateral side of this base formed by tubercles of the scaphoid and trapezium.medial side formed by pisiform & hook of hamate.

base

head

7

3. What is extensor retinaculum (dorsal carpal ligament)?

abductor pollicis longus & extensor pollicis brevisextensor carpi radialis longus & extensor carpi radialis brevisextensor pollicis longus

through three compartments on the lateral surface of the wrist.

The extensor tendons pass into the hand in six compartments defined by an extensor retinaculum:

extensor digitorum & extensor indicis posterior surface of the wrist

extensor carpi ulnaris & extensor digiti minimi medial side of the wrist

8

4. What is palmar aponeurosis?A triangular condensation of deep fascia that covers the palm and is anchored to the skin in distal regions.

Continuous with the palmaris longus tendon, when present; otherwise, anchored to the flexor retinaculum.

9

10

5. …Fibrous digital sheaths?Tendons of flexor digitorum superficialis and profundus cross the palm enter fibrous sheaths on the palmar aspect of the digits.

o formed by fibrous arches and cruciate (cross-shaped) ligaments

o hold the tendons to the bony plane

o prevent the tendons from bowing

when the digits are flexed. are surrounded by a synovial

11

6. What are extensor hoods for?Tendons of the extensor digitorum extensor pollicis longus muscles expand over the proximal phalanges to form "extensor hoods" or "dorsal digital expansions".

Tendons of the extensor digiti minimi, extensor indicis, extensor pollicis brevis join these hoods.

12

7. Which are the intrinsic muscles of the hand?Palmaris brevis

Interossei

Thenar muscles

Hypothenar muscles

Adductor pollicis

Lumbrical

Abductor pollicis brevis

Flexor pollicis brevis

Opponenspollicis

Abductordigiti minimi

Flexordigiti minimi

13

8. …functions the intrinsic muscles of the hand?

Palmar interosseiadduct the thumb, index, ring, and little fingers with respect to a long axis through the middle finger

Dorsal interosseimajor abductors of the index, middle, and ring fingers, at the metacarpophalangeal joints

14

8. …functions the intrinsic muscles of the hand?

Lumbricals

flexing metacarpophalangeal joints

extending interphalangeal joints

medial two deep branch of the ulnar nerve lateral two median nerve

15

8. …functions the intrinsic muscles of the hand?

Palmaris brevis

deepens cup of the palm by pulling on skin over the hypothenar eminence forming a distinct ridge.

This may improve grip.

16

9. How are the intrinsic muscles innervated?All of the intrinsic muscles of the hand by deep branch of the ulnar nerve

Exceptthree thenar & two lateral lumbrical musclesby median nerve

17

10. ....arteries of the hand?

Superficial palmar archDeep palmar arch

princeps pollicis artery

radialis indicis artery

• three palmar metacarpal arteries •three perforating branches

palmar digital artery

common palmar digital arteries

18

Before penetrating the back of the hand, the radial artery gives rise to two vessels:

dorsal carpal branch passes medially as the dorsal carpal arch, across the wrist dorsal metacarpal arteriesdorsal digital arteries

first dorsal metacarpal artery supplies adjacent sides of the index finger and thumb.

19

20

21

11....veins of the hand?Cephalic vein originates from lateral side of dorsal venous network. Basilic vein originates from medial side of dorsal venous network.

22

12. ...sensory innervation of the hand?

Ulnar nerve medial side of the palm, medial half of the dorsum of the hand, 5th finger, medial half of the 4th finger, anterior surfaces of medial ½ digitsMedian nerve palmar surfaces of the lateral 3 ½ digits and cutaneous regions over the dorsal aspects of the distal phalanges (nail beds) of the same digitsRadial nerve dorsolateral aspect of the palm, dorsal aspects of the lateral three,one-half digits distally to approximately the terminal interphalangeal joints

23

12. Median nerve

24

12. Ulnar nerve

25

12. Radial nerve

26

27

28

29

13. ...carpal tunnel?base of the carpal arch

formed medially by pisiform & hook of hamate

laterally by tubercles of scaphoid & trapezium

SLTP

TTCH

30

14. ....anatomical snuffbox?

lateral border tendons of abductor pollicis longus APLEPBextensor pollicis brevismedial border tendon of extensor pollicis longus

31

14. ....anatomical snuffbox?floor

scaphoid & trapeziumdistal ends of the tendons of extensor carpi radialis longus extensor carpi radialis brevis