Hand Anatomy

General hand anatomy

     Hand is distal part of the upper extremity. Hand has a bony skeleton, has muscles originate from bones and tendons. Muscles help to move. There are vessels and nerves which reach to hand. Veins of hand takes blood from it. The skin of the hand is thick in palmar region, is thin in dorsal region. Hand touches, grips, pinches and presses things. We take a look in detain in this article. We hope this article is useful for everyone who interests in medical sciences.

Bones of hand

     There are 8 carpal bones. There are two carpal rows, proximal and distal. Here are the names of carpal bones in Latin and in English.

Proksimal row: (Lateral to medial)
Os scaphoideum - Scaphoid
Os lunatum - Lunate
Os triquetrum - Triquetral
Os pisiforme - Pisiform

Distal row: (Lateral to medial)
Os trapezium - Trapezium
Os trapezoideum - Trapezoid
Os capitatum - Capitate
Os hamatum - Hamate

If you have a trouble to remember the names of carpal bones, see the sentences below.

She Likes To Play              Scaphoid     Lunate      Triquetrum  Pisiform
Try To Catch Her               Trapezium  Trapezoid  Capitate      Hamate

     Anterior to carpal bones there is flexor retinaculum. Median nerve and flexor tendons pass under the flexor retinaculum. Here is carpal tunnel.

     

     There are 5 metacarpal bones. Metacarpal bones are named as I, II, III, IV, V. Name of bone which forms finger is phalanx. First finger has 2 phalanx named as distal and proximal. Other fingers have 3 phalanxes named as distal middle and proximal.

     In anatomical position, the anterior side of hand is named as palmar and posterior side is named as dorsal. Sweat glands are in large number in palmar side. The skin in palmar side is thick and hairless. In palmar side, under the skin there is a thick, fibrous and triangular shaped structure. Name of this structure is palmar aponeurosis. Palmar aponeurosis protects the neuromuscular structures and increases grip.

     Radial artery and ulnar artery supplies the hand. Arteries form vascular arches. Digital arteries take the blood up to distal part of fingers. Lymph of medial part of hand is transferred to supratrochlear lymph nodes and then to the axillary lymph nodes. Lymph of lateral part of hand is transferred to the infraclavicular lymph nodes and then to the axillary lymph nodes.

     Radial nerve, median nerve and ulnar nerve reach to hand. Nerves supply hand (both motor and cutaneous sensory innervation).

 

     You can see the cunateous sensory innervation of hand below.

M= median nerve, U= ulnar nerve, R= raidal nerve, LACN= lateral antebrachial cutaneus nerve (musculocutaneous nerve), PACN= posterior antebrachial cutaneus nerve (radial nerve), MACN= medial antebrachial cutaneous nerve.

     

Muscles of hand

Muscles help to move thumb

M. abductor pollicis brevis - median nerve

M. flexor pollicis brevis - has 2 part, deep part ulnar nerve, superficial part median nerve

M. opponens pollicis - median nerve

M. adductor pollicis - ulnar nerve

Muscles help to move little finger

M. abductor digiti minimi - ulnar nerve

M. flexor digiti minimi brevis - ulnar nerve

M. opponens digiti minimi - ulnar nerve

M. palmaris brevis - ulnar nerve

Muscles help to move other fingers

M.m lumbricales - 1th and 2nd. median nerve, 3rd ve 4th ulnar nerve

Mm. interossei palmares - ulnar nerve

Mm. interossei dorsales - ulnar nerve