Hand Anatomy

A hand consists of several bones joined in a perfect manner because of which we are able to eat, write, lift, type, shave, clean, etc. We can locomote our hand in many different directions and positions. The wrist joint and the joints in fingers enable us to perform all types of activities.

Nerves, blood vessels, muscles, bones and joints, ligaments, and tendons are main parts of the human hand.

As the wrist and the hand consist of 27 bones, plastic surgeons, orthopedic surgeons, and the physiotherapists require exceptional skill to treat hand fractures or injuries. Take a look at the figure below. It shows the bones of the human hand.

The two parallel bones, the radius and the ulna of the forearm end near the wrist joint. The fibrocartilage separates the ulna from the wrist. The eight small bones of the wrist are recognized as carpal bones. The end of the forearm is connected to the hand with the help of thirteen bones.

The carpal bones of the wrist consist of two rows of bones, namely, the proximal row containing the scaphoid, lunate, and triquetrum (beginning with the thumb side) and the distal row consisting of the trapezium, trapezoid, capitate, hamate, and pisiform bones. All these bones play an important role in the anatomy of the wrist.

The bones of the hand (palm) are known as metacarpal bones. All five metacarpals together are recognized as the metacarpus. Wrist, palm, and fingers are thus made up of several small joints. All small carpal bones join the bones lying next to them, and thus make the anatomy of the human hand very complex.

The bones in the fingers and thumb are known as phalanges. The metacarpals are attached to phalanges. Proximal, middle, and distal are the three types of phalanges in the fingers.

Proximal phalanges are present at the start of the fingers. All fingers except the thumbs (also known as pollex) have middle phalanges. Distal phalanges are present at the end of the fingers. A thumb has proximal and distal phalanges. Eight carpal bones, five metacarpals, and fourteen phalanges (total 27 bones) comprise the hand.

Apart from the bones, nerves, muscles and tendons in the hand are important part of the hand structure. Fingertips have dense network of nerves. Flexor retinaculum and palmar aponeurosis are the two connective tissues which are present over the carpal bones and over the long tendons of the fingers respectively.

Another connective tissue known as palmar aponeurosis plays an important role in developing the ridges in the palm, because of which we can hold objects firmly. You must have heard about carpal tunnel syndrome, involving damaged median nerve resulting in pain in wrist and fingers or numbness in fingers. Radial and ulnar arteries provide blood to the hand.

Ulnar, radial, and median nerves along with the posterior antebrachial cutaneous play an important role in hand activities. A number of muscles promote the extension and abduction of the wrist and fingers. They also promote flexion, supination, circumduction, and pronation of the hand.

Performing hand and wrist strengthening exercises regularly can help prevent hand and wrist problems. Those who have come across hand or wrist injury, must have experienced severe unbearable pain, as the hand is made up of several joints.

Though surgeons study the anatomy of the hand in detail, correcting wrist or hand fractures involves tremendous skill. Only an experienced surgeon and physiotherapist can ensure normal movement of the hand after a serious injury.

Disclaimer: This is for informative purposes only, and should not be used as a replacement for expert medical advice.