Is it true that the human body has 206 bones, while China and Japan only have 204?

Usually adults have 206 bones, including skull, trunk and limbs. However, we China and Japanese only have 204 bones. This is because our fifth finger bone has only two joints, while Europeans and Americans have three joints, so China people have two fewer joints than Europeans and Americans.

Children have more bones than adults, generally 2 17 or 2 18. They are in the period of growth and development. Unformed bones, such as sacrum and coccyx, are usually connected together. When they grow up, several connected bones merge into one.

Human bones have different shapes and sizes, which can be divided into four types: long bones, short bones, flat bones and irregular bones. Among them, long bones are like sticks, short bones are like cubes, and flat bones are like flat slats. The longest bone in the human body is the femur on the thigh, which generally accounts for 27% of human height. There is a German named Constantine, whose femur is 75.9 cm long, which is the highest in the world. The three bones in the ear are the smallest bones in the human body, and the smallest stapes is only 0.25 ~ 0.43 cm long.

Human bones are very hard. Some people have done some tests, and each square centimeter of bone can bear 2 100 kg of pressure. Granite is very hard and can only bear 654,38+0,350 kilograms. Human skeleton is half water, half minerals and organic matter.

Generally speaking, the proportion of minerals in the bones of adults, especially the elderly, is relatively large, so the bones are hard and brittle and easy to fracture. Children, on the other hand, have a large proportion of organic matter, so their bones are tough, delicate and easy to deform. In contrast, men's bones are heavy and thick, while women's bones are light and thin; Fat people have smooth bone surfaces, while thin people have rough bone surfaces.