The cells of the tissues of the body undergo a life cycle that is controlled by the regulation of the genetic material within the nucleus of the cell. These regulations are based on internal signals that must maintain a stable relationship between the volume of the cell and the total surface are of the membrane. The cell’s life cycle is broken into three distinct phases, table 7. These phases are generally discussed as growth phase 1 (G1), normal growth of the cell, synthesis phase (S), replication of the genetic materials of the nucleus, and growth phase 2 (G2), replication of organelles to ensure enough are present for two cells. At the terminus of G2 phase, the cell will undergo a replication of itself referred to as mitosis that ends with the formation of two identical cells. The rate of growth and division of the cell is dependent of the type of cell, the genetic regulations of the cell and the combination of internal and external growth signals that the cell is receiving, figure 8. This process will continue until the cell is no longer able to complete the S phase within the cell life cycle at which point internal signals will trigger apoptosis (sequenced death) for the cell.