In order for cells to function as a whole there is a specific coordination between all the cells so that the organisms functions as a whole. Cells of one or more similar types are grouped together to form tissues, these tissues then combine to form organs, organs then arranged to form systems. This hierarchy enables the coordination needed to function to be achieved. Seen in figure 1.1, The concept of how the structures work together to produce the foundations of life is seen with the starting step of grouping muscle cells together to produce muscle tissues and then having a final product of a heart which is then able to work cohesively with other structures to create the circulatory system.