A great analogy one could use in understanding physiology is cooking! In physiology, we explore step-by-step changes that results in a final product. Cooking involves a number of steps as well. An error in any one of these steps could affect the final product. In cooking Mysore Pak (Split chick pea cake) for example, the timing is extremely crucial (the recipe is below). If it is cooked a little longer than the suggested time, the entire mixture is unusable. It does not hold the shape and becomes powdery. If it is undercooked, it is not Mysore Pak at all because it does not have the pores or the fragrance and lacks the dual color it develops while setting. In order to avoid such problems, one has to make sure that the cooking temperature is not too high or too low and the pan used is not too thin that makes the mixture burn easily.

The same is true for any physiological process. If one of the steps or ingredients is lacking or abnormal, the end product could be a disease state. Blood clotting is an example where calcium plays a key role. If calcium is in lower concentration than normal, it could interfere with the blood clotting process and be responsible for internal bleeding.  There are compensatory mechanisms that exist in the body to avoid such situations, however. To prevent low blood calcium levels, the body may begin to dissolve more bone matrix than normal or trigger increased calcium absorption.  

Mysore Pak (Split chick pea cake)

Boil sugar and water for 5 minutes. At the same time, heat ghee on medium, stir in split chick pea flour and fry for 5 minutes. Pour sugar syrup into the flour and ghee mixture and continue to stir while adding ghee little at a time. In approximately 15 to 20 minutes, the mixture turns stringy and pores appear. Empty this mixture into a greased container. Cut within 30 minutes.