BY PROF. ANSARI 28-10-07, 10.45 / 11.45 AM. SUNDAY. GROSS ANATOMY OF HAND BY PROF. ANSARI 28-10-07, 10.45 / 11.45 AM. SUNDAY.

Hand is the part of upper limb distal to wrist joint

LAND MARKS OF HAND The anterior aspect of hand is called palm. The posterior aspect is the dorsum of the hand. The skin on volar aspect is the thickest, hair free and sebacious glands are absent. The skin of palm is having flexural lines and dermatoglyphics patterns.

Land marks on palm At the base of thumb, is the ball of the thumb due to thenar muscles. At the root of the little finger is the ball of the little finger, due to hypothenar muscles. In the centre of the palm is the well of the palm. Fingers are numbered from lateral to medial as I, II,III,IV, V.

DORSUM OF THE HAND SURFACE FEATURES

BONES OF THE HAND

DERMATOMES OF PALM 1. Ulnar nerve area. 2.Median nerve area. 3. Radial nerve area. Skin on thumb side is supplied by C6 segment. Middle fingers are supplied by C7 segment. Little finger skin is supplied by C8 segment.

DERMATOMES ON THE DORSUM OF HAND 1.Skin on medial ½ of dorsum by ulnar nerve. 2. Skin of dorsal aspects of lateral 3 &1/2 fingers by median nerve. 3.skin on lateral ½ of dorsum of hand by radial nerve.

DEEP FASCIA OF THE HAND Palmar aponeurosis. Flexor retinaculum. Fibrous flexure sheets. Extensor retinaculum.

Deep fascia The palmar aponeurosis is a wide spread sheath of deep fascia over the well of the palm. It gives protection to the underlying vessels and nerves. The flexor retinaculum is a thickened band of deep fascia over the anterior aspects of carpal bones. It protects the tendons and median nerve, and forms carpal tunnel. Fibrous flexor sheaths are deep fascia thickening over the distal aspects of fingers ventrally.

THENAR MUSCLES Intrinsic muscles of thumb are:- Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis, and Adductor pollicis, and first dorsal interosseus.

INTRINSIC THENAR MUSCLES

HYPOTHENAR MUSCLES Abductor digiti minimi, Flexor digiti minimi, Opponens digiti minimi, Fourth palmar interoseous.

FLEXOR RETINACULUM

ATTACHMENTS OF FLEXOR RETINACULUM Medially attached to the scaphoid and trapezeum, Laterally it is attached to the hamate and pisiform bones. It gives attachments to thenar & hypothenar muscles. Above it ulnar artery and ulnar nerve passes in to the palm. Underneath it long flexor tendons of thumb and medial four digits pass along with the median nerve.

CARPAL TUNNEL It is an osteofascial tunnel formed by the flexor retinaculum & carpal bones. Transmits the flexor pollicis longus, flexor digitorum superficialis & profundus, and median nerve. Increase pressure over the contents of carpal tunnel will lead to carpal tunnel syndrome, a compression syndrome.

OTHER INTRINSIC MUSCLES Lumbricals, and Interossei.

LUMBRICALS Four lumbricals arise from the tendons of flexor digitorum profundus, and get inserted in to the dorsal digital expansions.

DORSAL DIGITAL EXPANSION

THE INTEROSSEI There are four dorsal interossei between the metacarpal bones. Dorsal interossei are bipennate muscles. Action of dorsal interossei is (DAB), abduction of the fingers. All interossei are supplied by the deep branch of ulnar nerve. Palmar interossei are three, unipennate muscles,action is (PAD),adduction at the MCP joints.

DORSAL & PALMAR INTEROSSEI

DORSAL VENOUS ARCH It is a venous network over the dorsum of hand. Each digit is drained by a pair of digital veins, these inturn joins with each other to form metacarpal veins,the metacarpal veins of adjacent sides unites with each other and form a venous arch, called dorsal venous arch. On the medial side the dorsal venous arch continues as basilic vein; On the lateral side it ascends as cephalic vein.

EXTENSOR RETINACULUM OF WRIST It is the thickening of the deep fascia over the dorsal aspect of wrist joint. It binds the long extensor tendons of the digits, and form six tunnels.

ANATOMICAL SNUFF BOX The boundaries are above by the tendon of the extensor pollicis longus and below by the tendons of extensor pollicis brevis and the abductor pollicis longus. Structures felt at the floor are styloid process of radius, trapezeum and scaphoid. Radial artery crosses the floor.

THE ARTERIAL ARCHES OF PALM The superficial palmar arch is due to the ulnar artery. The deep palmar arch is due to the deep branch of radial artery. That give rise to various branches that supply the palm structures and digits.

MEDIAN &ULNAR NERVES

MOVEMENTS OF WRIST

MOVEMENTS OF THUMB Neutral position opposition Reposition flexion abduction

FUNCTIONS OF THE HAND

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