Hand

Veins

- Deep follow aa. - Superficial Veins: drain into a dorsal venous network on the dosum

Carpal Archs

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

cephalic vein

originates from the lateral side of the dorsal venous network and passes over the anatomical snuffbox into the forearm.

basilic vein

originates from the medial side of the dorsal venous network and passes into the dorsomedial aspect of the forearm.

Nerves

...

Phalanges

14 on each hand

Metacarpals

I to V

Superficial Radial N

The only part of the radial nerve that enters the hand is the superficial branch passing over the anatomical snuffbox on the dorsolateral side of the wrist

Palmar aponeurosis

triangular condensation of deep fascia that covers the palm and is anchored to the skin in distal regions The apex of the triangle is continuous with the palmaris longus tendon, when present; otherwise, it is anchored to the flexor retinaculum

Contents of Carpal Tunnel

1. The four tendons of the flexor digitorum profundus, 2. the four tendons of the flexor digitorum superficialis, and 3. the tendon of the flexor pollicis longus pass through the carpal tunnel, 4. the median nerve

Carpal Bones

1. the boat-shaped scaphoid; 2. the lunate, which has a crescent shape; 3. the three-sided triquetrum bone; and 4. the pea-shaped pisiform 5. the irregular four-sided trapezium bone; 6. the four-sided trapezoid; 7. the capitate, which has a head; and (LARGEST) 8. the hamate, which has a hook

The deep palmar arch gives rise to

1. three palmar metacarpal arteries, which join the common palmar digital arteries from the superficial palmar arch; and 2. three perforating branches, which pass posteriorly between the heads of origin of the dorsal interossei to anastomose with the dorsal metacarpal arteries from the dorsal carpal arch

Carpal Joints

Although movement at the carpal joints (intercarpal joints) is limited, they do contribute to the positioning of the hand in abduction, adduction, flexion, and, particularly, extension

Carpal tunnel and structures at the wrist

The carpal tunnel is formed anteriorly at the wrist by a deep arch formed by the carpal bones and the flexor retinaculum

Pisiform

The pisiform is a sesamoid bone in the tendon of the flexor carpi ulnaris and articulates with the anterior surface of the triquetrum

Median Nerve

The recurrent branch of the median nerve innervates the three thenar muscles. Originating from the lateral side of the median nerve near the distal margin of the flexor retinaculum, it curves around the margin of the retinaculum and passes proximally over the flexor pollicis brevis muscle. The recurrent branch then passes between the flexor pollicis brevis and abductor pollicis brevis to end in the opponens pollicis. The palmar digital nerves cross the palm deep to the palmar aponeurosis and the superficial palmar arch and enter the digits. They innervate skin on the palmar surfaces of the lateral three and one-half digits and cutaneous regions over the dorsal aspects of the distal phalanges (nail beds) of the same digits. In addition to skin, the digital nerves supply the lateral two lumbrical muscles

Carpometacarpal Joints

The saddle joint, between metacarpal I and the trapezium, imparts a wide range of mobility to the thumb that is not a feature of the rest of the digits. Movements at this carpometacarpal joint are flexion, extension, abduction, adduction, rotation, and circumduction. The carpometacarpal joints between metacarpals II to V and the carpal bones are much less mobile than the carpometacarpal joint of the thumb, allowing only limited gliding movements. Movement of the joints increases medially, so metacarpal V slides to the greatest degree. This can be best observed on the dorsal surface of the hand as it makes a fist

Deep transverse metacarpal ligaments

The three deep transverse metacarpal ligaments (Fig. 7.93) are thick bands of connective tissue connecting the palmar ligaments of the metacarpophalangeal joints of the fingers to each other. They are important because, by linking the heads of the metacarpal bones together, they restrict the movement of these bones relative to each other. As a result, they help form a unified skeletal framework for the palm of the hand.

Ulnar nerve

The ulnar nerve enters the hand lateral to the pisiform and posteromedially to the ulnar artery The deep branch of the ulnar nerve passes with the deep branch of the ulnar artery

Allen's test

To test for adequate anastomoses between the radial and ulnar arteries, compress both the radial and ulnar arteries at the wrist, then release pressure from one or the other, and determine the filling pattern of the hand. If there is little connection between the deep and superficial palmar arteries, only the thumb and lateral side of the index finger will fill with blood (become red) when pressure on the radial artery alone is released.

Metacarpophalangeal joints

flexion, extension, abduction, adduction, circumduction, and limited rotation The capsule of each joint is reinforced by the palmar ligament and by medial and lateral collateral ligaments.

Interphalangeal joints of hand

hinge joints that allow mainly flexion and extension. They are reinforced by medial and lateral collateral ligaments and palmar ligaments

Wrist joint

radius and the articular disc overlying the distal end of the ulna, and the scaphoid, lunate, and triquetrum Because the radial styloid process extends further distally than does the ulnar styloid process, the hand can be adducted to a greater degree than it can be abducted.