What is the hand?
The most important gripping organ of the human body is divided into the carpus, metacarpus and fingers. The carpus is formed by eight small, squat bones, four of which are distributed over two transverse rows and named after their shape: Scaphoid, lunate, triangular and pea bones are arranged toward the forearm, while the greater and lesser polygonal bones, capitate and hooked bones are arranged toward the metacarpus. A mnemonic helps to remember the names: “If a barge sails in the moonlight in a triangle around the pea leg, polygon large and polygon small, at the head there must be a hook.”
These small bones are held tightly together by ligaments and form a vault with the arch facing upward. On the inside of a strong transverse ligament is a passageway for tendons and nerves that pull from the forearm into the palm, allowing movement and sensation. The carpal bones as a whole provide an articulated connection to both the forearm (ulna, radius) and the metacarpals.
The fingers are composed of 14 individual elongated bones, which – like the 14 toe bones on the foot – are divided as follows: The thumb (like the big toe) is composed of only two bones, the proximal and distal or nail phalanges. The remaining fingers (or toes) are composed of three bones each: Basal phalanx, middle phalanx, and distal or nail phalanx.
What is the function of the hand?
The main function is gripping. The thumb plays a decisive role in this, as it is the only finger that can form a pair of pincers with all the other fingers. But it is not only the gripping function that makes the hand special: Due to the numerous tactile corpuscles, of which particularly many are located in the fingertips, it is also an important sensory organ that can even develop to a very high level through special training – as is necessary, for example, for blind people to orient themselves and read Braille.
Where is the hand located?
It forms the end of the arm just as the foot forms the end of the leg. It is connected to the forearm by the wrist.
