Food and body cells

Food is needed for growth and repair. Our body is made up of millions of units called cells. When growth takes place, new cells are added to the existing ones. The existing ones also increase in size. On the other hand, cells do get worn out and die. These cells have to be replaced. This process is called repair. For both growth and repair, proteins are necessary. The other major physiological functions performed by food are the protective and regularity functions. Protective refers to the role in preventing infection by ensuring proper functioning of the body systems responsible for fighting infections. Even if, a person does develop an infection or any other type of illness, food and the nutrients it contains facilitate rapid recovery. A person eating a poor diet would take much longer to recover and he would fall sick more easily. The regularity function refers to the role of food in controlling body processes, such as the beating of heart, maintainence of body temperature and contraction of muscles. Each of these processes is controlled, for instance, our body temperature is maintained at 98.4 degrees F or 37 degrees C. Similarly, the rate at which the heart beats is also maintained between 60 to 100 pulse rate per minute. This is achieved by certain specific nutrients like vitamins, minerals and proteins and water. These contribute substantially to both protective and regulatory functions. The heart, blood and blood vessels work together to service the cells of the body. Using the network of arteries, veins and capillaries, blood carries carbon dioxide to the lungs (for exhalation) and picks up oxygen. From the small intestine, the blood gathers food nutrients and delivers them to every cell.