How do hands work

All three nerves originate at the shoulder and travel down the arm to the hand. Each of these nerves has sensory and motor components. Median Nerve: The median nerve crosses the wrist through a tunnel called the carpal tunnel. The median nerve provides sensation to the palm, thumb, index finger, middle finger, and part of the ring finger. Radial Nerve: The radial nerve runs down the thumb side of the forearm and provides sensation to the back of the hand from the thumb to the middle finger.

Blood vessels travel beside the nerves to supply blood to the hand. The main arteries are the ulnar and radial arteries, which supply blood to the front of the hand, fingers, and thumb. The radial artery is the largest artery of the hand, traveling across the front of the wrist, near the thumb. Pulse is measured at the radial artery. Other blood vessels travel across the back of the wrist to supply blood to the back of the hand, fingers, and thumb.

Bursae are small fluid filled sacs that decrease friction between tendons and bone or skin. Bursae contain special cells called synovial cells that secrete a lubricating fluid. The anatomy of the human hand is very complex. Normal hand function requires all the various bones and soft tissues that structurally form the hand to maintain proper alignment and control.

Any condition or injury that disrupts this anatomy greatly impacts the function of the hand and the ability to perform activities of daily living.

Patient Education Library. Metacarpals are the middle part of the hand bones. Carpals are the wrist bones. Joints are places where bones fit together, allowing movement. Ligaments are soft tissues that connect bone to bone and stabilize your joints.

Muscles are soft tissues that tighten and relax to move your hand. The synovial lining makes the fluid inside your joints that helps make movement smooth.

Volar plates are hard tissues that stabilize the joints, keeping fingers from bending backward. Tendon sheaths are fluid-filled tubes that surround, protect, and guide the tendons. There are 3 major types of bones in the hand itself, including:. The 14 bones that are found in the fingers of each hand and also in the toes of each foot. Each finger has 3 phalanges the distal, middle, and proximal ; the thumb only has 2. Carpal bones. Yes, there most definitely is — in fact most of the palm area of the hand is muscular.

On the lighter side, here is a 3D animation showing the same thing and particularly explaining carpel tunnel syndrome. Can you believe that the main nerve running into the hand starts in the neck? So there you have it!