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:

    Another hand thy sword shall wield,
    Another hand the standard wave,
    Till from the trumpet’s mouth is pealed
    The blast of triumph o’er thy grave.
    William Cullen Bryant (1794–1878)

    ...that broken reed of a staff, which will pierce the hand of anyone who leans on it.
    Bible: Hebrew, 2 Kings 18:21.

    I ... would rather be in dependance on Great Britain, properly limited, than on any nation upon earth, or than on no nation. But I am one of those too who rather than submit to the right of legislating for us assumed by the British parliament, and which late experience has shewn they will so cruelly exercise, would lend my hand to sink the whole island in the ocean.
    Thomas Jefferson (1743–1826)