Address the need to get oxygen to the muscles and get rid of co2, as well as how the muscles cells get the energy needed to continue contracting.

When we breathe, oxygen enters our lungs. Through blood, oxygen is transported from the lungs to all cells of the body, including muscle cells. Carbon dioxide is taken from cells and through blood, transported to the lungs. On the other hand, oxygen in the muscle cells is used for cellular respiration which one stage is a formation of ATP. ATP is used as the energy for the muscle cell contraction.