What do hands do

Wrist retinacula…. The elbow is one of the largest joints in the body. In conjunction with the shoulder joint and wrist, the elbow gives the arm much of its versatility…. The distal phalanges are one of three types of finger bones. The human hand and wrist are comprised of three different bone groups.

The carpals are…. Health Conditions Discover Plan Connect. Read this next. Thumb Medically reviewed by the Healthline Medical Network. Epiglottis Medically reviewed by the Healthline Medical Network.

Medically reviewed by William Morrison, M. Female Pelvis Overview. Diaphragm Overview. Spleen Medically reviewed by the Healthline Medical Network.

Knee Medically reviewed by the Healthline Medical Network. Chimanzees and monkees can oppose the thumb to the index digit. What makes the human hand unique in the animal kingdom is the ability of the small and ring fingers to rotate across the palm to meet the thumb , owing to a unique flexibility of the carpometacarpal joints of these fingers, down in the middle of the palm.

This is referred to as "ulnar opposition" and adds unparalleled grip, grasp, and torque capability to the human hand. This feature developed after the time of Lucy, a direct human ancestor, who lived about 3. Fingernail feeling Do fingernails have feeling? No, but the fingernail extends deep beneath and behind the skin of the cuticle, and nerves on the back of the finger around the cuticle sense forces transmitted from the tip of the fingernail.

The brain integrates the sensations from the nerves of both the fingertip pad and cuticle to give a complex enhanced perception of pressure and shear at the fingertips. Loss of a fingernail changes the feeling on the palm side of the fingertip. Hand words A number of the English words which describe parts of the hand are ancient, with origins buried in the roots of language itself, suggesting a basic relationship between the development of the hand and the development of language.

Hand and Brain About a quarter of the motor cortex in the human brain the part of the brain which controls all movement in the body is devoted to the muscles of the hands. This is usually illustrated with a drawing of a human figure draped over the side of the brain, body parts sized proportional to the amount of brain devoted to their movement, referred to as a homunculus - as illustrated in this drawing from Dr. Hair and nails Structurally, fingernails are modified hairs.

Carpal tunnel syndrome In one study , carpal tunnel syndrome was found in 9 percent of women between the ages of 25 and The skin of the palm The skin on the palm side of the hand and fingers is unique for these reasons and more: No hair the medical term is glabrous.

Usually neither color nor the ability to tan. Tough and durable, yet sensitive. Anchored down to the bones beneath through an intermediate layer of fascia. This arrangement keeps the skin of the palm from sliding around like a rubber glove when we use our hands to grip and twist.

In some people, this layer of fascia shrinks and thickens, leading to Dupuytren's disease. Overlapping fingers When one curls the fingers into a fist, the fingertips naturally group together side by side.

If the fingertips all bend together, they continue into the palm side by side. However, the natural tendency is for each fingertip to aim for the same point at the base of the thumb , which is obvious when touching each finger down to the base of the palm. For this reason, if a hand problem stiffness, swelling, etc.

Urban legends "If you can move your finger, it isn't broken" False. Curved fingers Fingers are never perfectly straight. Usually, the index, ring and small finger each curve sideways slightly toward the middle finger, and the middle finger may curve toward either side. The finger bones are straight on the back side, but curved on the palm side. When we bend our fingers into a fist, the finger bones produce a shape similar to a circle in a square , round on the inside, square on the outside.

When we make a fist, the fingertips curve through a spiral, not a circle. This is because the lengths of the finger bones are related in a way seen often in naturally occuring spirals. These spirals in turn relate to a mathematical series of numbers discovered by Fibonacci in In this series, each number is the sum of the previous two numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21, The lengths of the finger bones approximate the ratio of the Fibonacci numbers 2, 3, 5, and 8.

Parts of a Hand Hands are made up of more bones and moving parts than most other areas of the body. Bones are hard tissues that give your hand shape and stability. Phalanges are the finger bones. 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.