The hand contains 3 parts - the wrist, metacarpals, and digits. It has 8 carpal bones in the wrist, 5 metacarpals, and 14 phalanges in the fingers. The hand has intrinsic muscles in the thenar, hypothenar, and central groups that control thumb and finger movement. Nerves like the median and ulnar innervate these muscles. Potential spaces in the hand can become infected.

2. The Hand
Dr. Hassan Abdel Raheem Hassan
Assistant Prof. of Anatomy
College of Medicine, Jouf University

3. The hand is the region of the upper limb distal to the wrist
joint.
It is subdivided into three parts:
■ wrist (carpus),
■ metacarpus, and
■ digits (five fingers)
The hand has an anterior surface (palm) and a dorsal
surface (dorsum of hand)
The hand

4. Bones: three groups of bones in the hand:
I. Eight carpal bones: are the bones of the wrist, arranged in two rows
1. Proximal row: scaphoid, lunate, triquetrum, and pisiform
2. Distal row: trapezium, trapezoid, capitate and hamate
II. five metacarpals (I to V): Each metacarpal consists of a base, a shaft
(body),and, a head
III. Phalanges:
- are the bones of the digits, Each has a base, a shaft (body), and a head.
-The thumb has two (a proximal and a distal phalanx).
- The rest of the digits have three(a proximal, a middle, and a distal phalanx).
The hand

5. Intrinsic Muscles of The Hand
1.LATERAL GROUP
FOUR THENAR MUSCLES
2. MEDIAL GROUP
THREE HYPOTHENAR MUSCLES
4. PALMARIS BREVIS
3.CENTRAL GROUP
FOUR LUMBRICALS
FOUR PALMAR INTEROSSEI
FOUR DORSAL INTEROSSEI

6. Movements of thumb

7. Intrinsic Muscles of The Hand
I. ThenarGroup
II. Hypothenar muscles

8. I.Thenarmuscles
1.Abductor Pollicis Brevis: Abducts thumb
2.Flexor Pollicis Brevis: Flexes thumb
3.Opponens Pollicis: Medially rotates thumb, so bringing the pad of the thumb into a position facing the
pads of the fingers
4.Adductor Pollicis Muscle: -adducts the thumb
II. Hypothenar muscles
1. Opponens Digiti Minimi: rotates metacarpal V toward the palm
2.Abductor Digiti Minimi: Abducts little finger at metacarpophalangeal joint
3.Flexor Digiti Minimi Brevis: Flexes little finger at metacarpophalangeal joint
Intrinsic Muscles of The Hand

9. A. interossei muscles: are muscles between and attached to the
metacarpals
Two groups :
1. Palmar interossei (three or four muscles): numbered first,second,
third, and fourth from lateral to medial side
Action: Adduction of the thumb, index, ring, and little fingers at the
metacarpophalangeal joints
2. Dorsal interossei: four muscles, numbered first,second, third, and
fourth from lateral to medial side
Action: Abduction of index, middle, and ring fingers at the
metacarpophalangeal joints
Intrinsic Muscles of The Hand
III. CENTRAL GROUP

10. B. Lumbrical muscles: There are four lumbrical (worm-
like) muscles, and numbered first,second, third, and fourth
from lateral to medial side.
Action: flexion the metacarpophalangeal joints and
extension of the interphalangeal joints.
Intrinsic Muscles of The Hand

11. IV. Palmaris Brevis: Wrinkles the skin of the hypothenar eminence and deepens the hollow of the palm
Intrinsic Muscles of The Hand

12. Nerves In Hand
ULNAR NERVE:
➢Superficial Branch:
• Palmaris brevis
➢Deep Branch:
• Adductor pollicis
• Hypothenar muscles
• Interossei
• Medial two lumbricals
MEDIAN NERVE:
• Abductor pollicis brevis
• Flexor pollicis brevis
• Opponens pollicis
• Lateral two lumbricals

13. ULNAR NERVE MEDIAN NERVE
Nerves In Hand

14. Palmar Aponeurosis
Def: It is a thickening of deep fascia in the middle of the palm
shape: triangular, has
 Apex: directed proximally, continuous with tendon of palmaris longus
 Base: directed distally, divided into 4 slips for the medial 4 fingers
Functions: It protects the underlying tendons, vessels & nerves
Palmar Aponeurosis

15. The carpal tunnel: is a passage to the palm of the hand.
BOUNDARIES:
1.Posterior: Carpal arch formed by carpal bones
2. Anterior: Flexor Retinaculum
CONTENTS:
1. Tendons of flexor digitorum superficialis (FDS).
2. Tendons of flexor digitorum profundus (FDP)
3. Tendon of flexor pollicis longus (FPL).
4. Median nerve
Carpal tunnel

16. Def: potential spaces filled with loose connective tissue .
Importance: may get infected and distended with pus.
Spaces of the hand
1.Midpalmar space:
Location: It lies in the medial half of the hollow of the palm.
Extension: proximally till the distal margin of flexor retinaculum, distally till the distal palmar crease.
2.Thenar space:
Location: It lies in the lateral half of the hollow of the palm.
Extension: proximally till the distal margin of flexor retinaculum, distally till the distal palmar crease.

17. 3. pulp spaces of the digits: subcutaneous spaces on the palmar side of tips of the fingers and thumb.
4. Space of Parona(Forearm space):
fascial interval underneath the flexor tendons on the front of distal part of the forearm
Spaces of the hand

18. Anatomical snuffbox: depression formed on the posterolateral side of the wrist and metacarpal I by the extensor
tendons passing into the thumb
Anatomical snuffbox