Hand

A hand (med./lat.: manus, pl. manūs) is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "hand" and fingerprints remarkably similar to human fingerprints) are often described as having either "hands" or "paws" on their front limbs.

Hands are the main structures for physically manipulating the environment, used for both gross motor skills (such as grasping a large object) and fine motor skills (such as picking up a small pebble). The fingertips contain some of the densest areas of nerve endings on the body, are the richest source of tactile feedback, and have the greatest positioning capability of the body; thus the sense of touch is intimately associated with hands. Like other paired organs (eyes, feet, legs), each hand is dominantly controlled by the opposing brain hemisphere, so that handedness, or the preferred hand choice for single-handed activities such as writing with a pencil, reflects individual brain functioning.

Some evolutionary anatomists use the term hand to refer to the appendage of digits on the forelimb more generally — for example, in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand.

The human hand has 27 bones, 14 of which are the phalanges (proximal, medial, and distal) of the fingers. The metacarpal is the bone that connects the fingers and the wrist. Each human hand has 5 metacarpals.

Read more about Hand:  Definitions, Evolution, Additional Images

Famous quotes containing the word hand:

    It is fair to assume that when women in the past have achieved even a second or third place in the ranks of genius they have shown far more native ability than men have needed to reach the same eminence. Not excused from the more general duties that constitute the cement of society, most women of talent have had but one hand free with which to work out their ideal conceptions.
    Anna Garlin Spencer (1851–1931)

    All who wish to hand down to their children that happy republican system bequeathed to them by their revolutionary fathers, must now take their stand against this consolidating, corrupting money power, and put it down, or their children will become hewers of wood and drawers of water to this aristocratic ragocracy.
    Andrew Jackson (1767–1845)

    And if any mischief follow, then thou shalt give life for life, eye for eye, tooth for tooth, hand for hand, foot for foot, burning for burning, wound for wound, stripe for stripe.
    Bible: Hebrew Exodus, 21:23-25.