Cell of the living units of the body

Cell of the living units of the body:

The basic living unit of the body is the cell. Each organ is an aggregate of many different cells held together by inter-cellular supporting structures. Each type of cell is specially adapted to perform one or a few particular function. For instance, the red blood cells, numbering 25 trillion in each human being, transport oxygen from the lungs to the tissues. Although the red cells are most abundant of any single type of cell in the body, there are about 75 trillion additional cells of other types that perform functions different from those of the red cell. The entire body, then contain about 100 trillion cells.

Although the many cells of the body often differ markedly from one another, all them have certain basic characteristic that are alike. For instance, in all cells, oxygen reacts with carbohydrates, fat, and protein to release the energy required for cell function. Further, the general chemical mechanisms for changing nutrients into energy are basically the same in all cells, and all cells deliver end products of their chemical reactions into the surrounding fluids. Almost all cells also have the ability to reproduce additional cells of their own kind. Fortunately, when cells of a particular type are destroyed from one cause or another, the remaining cells of this type usually generate new cells until the supply is replenished.