Neanderthal thumbs better adapted to holding tools with handles

Neanderthal thumbs were better adapted to holding tools in the same way that we hold a hammer, according to a paper published in Scientific Reports. The findings suggest that Neanderthals may have found precision grips—where ...

How consumers responded to COVID-19

The unpredictability of the COVID-19 pandemic and its impact on people's daily lives has facilitated changes ranging from social interactions to purchasing behavior. Adjusting to the many disruptions may seem difficult, but ...

Researchers produce low-cost hand sanitizer from waste

A Tel Aviv University breakthrough allows, for the first time, a local production of ethanol—and hand sanitizer—based on plant and paper waste, using a novel lignin (a substance found in plants) degradation process. This ...

Wrong number of fingers leads down wrong track

Have you ever wondered why human hands have five fingers? And what about amphibians? They usually only have four. Until now, researchers assumed that this was the case with the early ancestors of today's frogs and salamanders, ...

Homo erectus hand ax found in East Africa

A team of researchers from Japan, Hong Kong and Ethiopia has found a hand ax that they believe was made by a possibly direct human ancestor in what is now modern Ethiopia. In their paper published in Proceedings of the National ...

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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 chief organs 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 pen, 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 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.

This text uses material from Wikipedia, licensed under CC BY-SA