ANATOMY&PHYSIOLOGY FOR NURSES

THE TISSUE CELL On the other hand, the cell needs a supply of energy for its activities and it will use some absorbed food materials as a fuel. The food is broken down and the energy stored in it is released and used by the cell. These destructive activities of the cell are called catabolism. Anabolism and catabolism make up the total activities of the cell.  or metabolism. The waste materials resulting from the catabolic processes are eliminated from the cell into the interstitial fluid, and thence carried away by the blood.  The blood transports the carbonic acid waste to the lungs where it is removed from the body as carbon dioxide. The other waste substances are eliminated, via the Kidneys, in the urine. The blood is also responsible for bringing to the cell its oxygen and other food requirements.                In describing the structure of the cell it is essential to relate its parts to its function. The protoplasm of the cell is composed of a centrally placed body, the nucleus, and the cytoplasm or remainder of the protoplasm, which surrounds the nucleus. CYTOPLASM.  This contains the following essential requirements: 1.Mitochondria, small rod-like structures which are closely connected with the catabolic, or respiratory, processes of the cell body. 2.Golgi apparatus. A canal-like structure lying next to the nucleus and involved in the secretory activities of the cell. 3.Ground cytoplasm.  A highly complex colloidal material in which the other structures are embeded. it is largely concerned with the anabolic, or synthetic, activities of the cell. 4. Centrosome. It is a minute dense part of the cytoplasm,mlying close to the nucleus. It plays ans important part during cell division. 5.Cell membrane. The cell boundary is no static envelope. Many important functions are connected with it, but in particular it acts as a selective sieve through which certain substances are allowed to pass into the cell, or which prevents other substances from gaining access to it. Thus it is most important in maintaining the correct chemical composition of protoplasm