EducationThe science

How many bones does a man have?

Surely, many people at least once thought about how many bones a person has. It is thanks to the presence of a large number of bones that people perform fairly complex manipulations with their fingers, flex and unbend their body, and it is the bones that protect the internal organs from external influences. The skeleton of a newborn child consists of more than three hundred bones. However, as a man grows up, some bones coalesce, so in the adult body the number of bones is approximately 206-208. Strangely enough, it sounds, but it is accurate to say how many bones a person does not seem possible.

When a person is born, his bones are soft enough, but eventually they become firmer and some of them grow together. For example, on the skull of a baby there are so-called fontanelles - places where connective tissue is present, which will later be replaced by a bone tissue. Later in the place of the fontanel, the bones coalesce, and this place becomes hardly discernible. About how many bones a person has, in different sources, different information is indicated, but one can say for sure that there are more than two hundred of them.

Human bones are sometimes compared to steel in terms of hardness, but they are much easier due to their porous structure. Bone tissue is formed from cells and intercellular substance, which is rich in mineral components. Outside, each bone is covered with a periosteum, which, in turn, is permeated with numerous blood vessels that feed the bone. The structure of human bones is such that they are absolutely insensitive, nerve endings are present only in the periosteum. In childhood, the advantage in the bone tissue of organic substances gives bones elasticity and elasticity. In older people, and especially in the elderly, the predominance of inorganic substances causes the fragility of bones.

The structure of the bones , as well as their shape, are very different. In the human body there are flat bones, tubular and mixed, as well as airy bones. To tubular bones it is customary to include long (femoral and humerus, shins, forearm bones) and short (bones of metatarsus, pasterns, phalanges of fingers). The relief of bones, as well as their shape, directly depend on the way the muscle tissue is attached to them. If the muscle connects to the bone tissue with the help of tendons, a comb, a hillock or an appendix is formed at the junction. If the muscular tissue is combined directly with the periosteum, a deepening is formed at the junction.

Inside the bone, in the cells of the spongy substance and the medullary cavity, the bone marrow is located. Newborns in all bones of the skeleton contain red bone marrow, which performs protective and hematopoietic functions. It is a network of special reticular fibers and cells. In adults, the red bone marrow contains only the cells of the spongy substance of the flat bones. In the bone marrow cavities of the tubular bones there is a yellow bone marrow, which is represented by a reincarnated reticular stroma with fatty inclusions.

The thickest bone in the human body is the femur. It is extremely difficult to break, but fracture of this bone can lead to quite serious consequences. Near the femur is an artery, if damaged, a person can lose a lot of blood.

How many bones for a person, to say, really, is quite difficult. Different people have different numbers of bones. For example, some have extra ribs, and someone has a sixth finger. Approximately one person out of twenty has an extra rib, which is interesting - in men, the presence of excess ribs is more common than in the fair sex. Some people have several additional bones located in the arches of the feet.

Similar articles

 

 

 

 

Trending Now

 

 

 

 

Newest

Copyright © 2018 en.birmiss.com. Theme powered by WordPress.