Mammals are a class of vertebrates characterized by that mothers feed their young through moms. This feature derives its name. This is because to treat complex animals, they need to be longer depending on the mother after birth, to acquire knowledge of this species. Like many other mammals, human beings are whose; i.e., to run our body we need to maintain certain internal temperature constant, close to 37 degrees Celsius. With this temperature, managed to keep the heart working, muscles on alert, the nervous system functioning, moving the intestines.

partial discharges to keep all this activity, we obtain our energy only food. According to the food chain, the human species obtains nutrients and energy from plants and animals. Power ranges from food to our body, to develop various functions using transformations of energy. Take, for example, a loaf of bread. The bread is made of wheat, which has basically carbohydrates, or stored chemical energy.

When the bread you eat, your body takes that energy. Then, you can store it, or use it immediately to move, to maintain the temperature, to operate the nervous system. Thus, the organism transforms chemical energy in food into mechanical energy (movement), thermal energy (heat) and electricity (transmission of nerve impulses).