hand

Eva Rudolf-Müller is a freelance writer in the medical team.She studied human medicine and newspaper sciences and has repeatedly worked in both areas - as a doctor in the clinic, as a reviewer, and as a medical journalist for various specialist journals. She is currently working in online journalism, where a wide range of medicine is offered to everyone.

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The hand, like the foot, is a highly complex structure made up of numerous individual parts: 27 bones, 36 joints and 39 muscles as well as various tendons and ligaments combine to form a versatile tool that has evolved into our most important organ of grasping and touching. Read everything you need to know about the anatomy and function of the hand as well as common injuries and illnesses!

What is the hand

The most important grasping organ of the human body is divided into the wrist, metacarpal and finger. The wrist is formed by eight small, squat bones, each of which is divided into four rows in two transverse rows and named after their shape: scaphoid, moonbone, triangular and pea bones are arranged in the direction of the forearm, the large and small polygonal bones, the headbone and hooked bones in the direction Metacarpal. A donkey bridge helps to remember the names: "If a boat drives in the moonlight in a triangle around the pea leg, polygon large and polygon small, there must be a hook on the head."

These small bones are held tightly together by ligaments and form an arch with the curvature upwards. On the inside of a strong, transverse band, there is a passage point for tendons and nerves that pull from the forearm into the palm of the hand and thus enable movement and sensory perception. The carpal bones as a whole represent an articulated connection both to the forearm (ulna, radius) and to the metacarpal bones.

The metacarpal consists of five bones (metacarpals), which are numbered in Roman numerals from I to V, and forms the palm. There is a well-articulated joint between the first metacarpal bone (which continues to the thumb) and the large polygonal bone. Thanks to this, the thumb is the only finger that can be placed opposite all other fingers - irreplaceable for grasping and holding objects. The remaining four metacarpal bones are articulated to the carpal bones by tight ligaments and - like these - form an arch. If you make a fist, you can clearly see the heads of the metacarpals because they protrude as spherical protrusions from under the skin.

The fingers are made up of 14 individual elongated bones, which - like the 14 toe bones on the foot - are divided as follows: The thumb (like the big toe) consists of only two bones, the base and the end or nail member. The remaining fingers (or toes) each consist of three bones: base, middle and end or nail.

What is the function of the hand?

The main function is grasping. The thumb plays a crucial role here, as it is the only finger that can form a pair of pliers with all the other fingers. But it's not just the gripping function that makes the hand something special: Due to the numerous tactile bodies, a particularly large number of which are located in the fingertips, it is also an important sensory organ that can even develop very highly through special training - such as for It is necessary for the blind to orientate themselves and to read the Braille.

Where is the hand?

It forms the end of the arm just as the foot forms the end of the leg. It is articulated to the forearm via the wrist.

What problems can the hand cause?

The carpal bones are particularly prone to injury: if you fall on your outstretched hand in a bicycle accident, for example, the result is often a fracture that affects the navicular bone in 70 percent of cases. Finger dislocations (finger dislocations) and broken fingers (finger fractures) are also common injuries. In carpal tunnel syndrome, the middle arm nerve is constricted in the bony connective tissue passage on the wrist. The consequences are sensory disturbances in the fingers, ranging from slight paresthesia to paralysis. Joint wear and tear (osteoarthritis), joint inflammation (as in rheumatoid arthritis), inflammation of the bones (osteomyelitis), and gout are other possible diseases that can affect the hand, among others.

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