hand

1 the (prehensile) extremity of the superior limb; "he had the hands of a surgeon"; "he extended his mitt" [syn: manus, mitt, paw]

2 a hired laborer on a farm or ranch; "the hired hand fixed the railing"; "a ranch hand" [syn: hired hand, hired man]

3 something written by hand; "she recognized his handwriting"; "his hand was illegible" [syn: handwriting, script]

4 ability; "he wanted to try his hand at singing"

5 a position given by its location to the side of an object; "objections were voiced on every hand"

6 the cards held in a card game by a given player at any given time; "I didn't hold a good hand all evening"; "he kept trying to see my hand" [syn: deal]

7 one of two sides of an issue; "on the one hand..., but on the other hand..."

8 a rotating pointer on the face of a timepiece; "the big hand counts the minutes"

9 a unit of length equal to 4 inches; used in measuring horses; "the horse stood 20 hands"

10 a member of the crew of a ship; "all hands on deck"

11 a card player in a game of bridge; "we need a 4th hand for bridge" [syn: bridge player]

12 a round of applause to signify approval; "give the little lady a great big hand"

13 terminal part of the forelimb in certain vertebrates (e.g. apes or kangaroos); "the kangaroo's forearms seem undeveloped but the powerful five-fingered hands are skilled at feinting and clouting"- Springfield (Mass.) Union

14 physical assistance; "give me a hand with the chores" [syn: helping hand]

1 place into the hands or custody of; "hand me the spoon, please"; "Turn the files over to me, please"; "He turned over the prisoner to his lawyers" [syn: pass, reach, pass on, turn over, give]

2 guide or conduct or usher somewhere; "hand the elderly lady into the taxi"

see Hand

English

Etymology

hand. Cognate with Dutch hand, German Hand, Swedish hand.

Pronunciation

• /hænd/, /h}

Dutch

Pronunciation

What constitutes a hand?

Many mammals and other animals have grasping appendages similar in form to a hand such as paws, claws, and talons, but these are not scientifically considered to be hands. The scientific use of the term hand to distinguish the terminations of the front paws from the hind ones is an example of anthropomorphism. The only true hands appear in the mammalian order of primates. Hands must also have opposable thumbs, as described later in the text.

Anatomy of the human hand

The human hand consists of a broad palm (metacarpus) with 5 digits, attached to the forearm by a joint called the wrist (carpus). The back of the hand is formally called the dorsum of the hand.

Digits

The four fingers on the hand are used for the outermost performance; these four digits can be folded over the palm which allows the grasping of objects. Each finger, starting with the one closest to the thumb, has a colloquial name to distinguish it from the others:

• index finger (med./lat.:digitus secundus manus), pointer finger, or forefinger
• middle finger (med./lat.:digitus me´dius)
• ring finger (med./lat.:digitus annula´ris)
• little finger (med./lat.:digitus mi´nimus ma´nus) or 'pinky'

Bones

The human hand has 27 bones: the carpus or wrist account for 8; the metacarpus or palm contains 5; the remaining 14 are digital bones, your fingers and thumb. The eight bones of the wrist are arranged in two rows of four. These bones fit into a shallow socket formed by the bones of the forearm. The bones of proximal row are (from lateral to medial): scaphoid, lunate, triquetral and pisiform.

Human hands contain 14 digital bones, also called phalanx bones: 2 in the thumb (the thumb has no middle phalanx) and 3 in each of the four fingers. These are:

• the distal phalanx, carrying the nail,
• the middle phalanx and
• the proximal phalanx.

Articulations

Also of note is that the articulation of the human hand is more complex and delicate than that of comparable organs in any other animals. Without this extra articulation, we would not be able to operate a wide variety of tools and devices. The hand can also form a fist, for example in combat, or as a gesture.

The articulations are:

• interphalangeal articulations of hand
• metacarpophalangeal joints
• intercarpal articulations
• wrist (may also be viewed as belonging to the forearm.)

Muscles and tendons

The movements of the human hand are accomplished by two sets of each of these tissues. They can be subdivided into two groups: the extrinsic and intrinsic muscle groups. The extrinsic muscle groups are the long flexors and extensors. They are called extrinsic because the muscle belly is located on the forearm.

Variation

Some people have more than the usual number of fingers or toes, a condition called polydactyly. Others may have more than the typical number of metacarpal bones, a condition often caused by genetic disorders like Catel-Manzke syndrome. The average length of an adult male hand is 189 mm, while the average length of an adult female hand is 172 mm. The average hand breadth for adult males and females is 84 and 74 mm respectively.

Additional images

See also

• Hand strength
• Dermatoglyphics
• Digit ratio
• Handanalysis
• Hand fetishism
• Handstand
• Hand walking
• Pentadactyl limb
• Reflexology
• Handedness

References

External links

portalpar Biology

• Hand injuries and diseases (Handuniversity.com)
• Hand anatomy (eMedicine)
• Interesting facts about the hands