Thousands of chemical and physical events take place in the depths of the body outside the individual’s knowledge and will. For example, human beings cannot decide on their height or the size of their organs. It is the growth hormone secreted by the pituitary gland that does this, under Allah’s inspiration. The growth process takes place in two different ways. Some cells increase their volume. Some cells divide and multiply. Growth hormone acts on all the body’s cells. Every cell understands the meaning of the message reaching it from the pituitary gland. If it needs to grow, it grows, and if it needs to divide and multiply, that is what it does. For example, a newborn baby’s heart is about one-sixteenth the size of an adult’s. However, it contains the same number of cells as an adult heart. During the development stage, the growth hormone acts on each individual heart cell. Each cell develops to the extent commanded by the growth hormone. Thus the heart grows and turns into an adult one.
Other cells in the body, muscle and bone cells for instance, divide and multiply through the developmental phase. It is, again, the growth hormone that tells these cells how much to divide. This is a most miraculous phenomenon, because a piece of flesh no larger than a chickpea, the pituitary gland, directs all the cells in the body and enables them to grow by either increasing their volume or dividing and multiplying. This immaculate order, once again, shows us the perfection in Allah’s creation. These cells have no means of seeing outside the human body and no means of knowing how much the body needs to grow and at which point to stop growing. With this flawless system created by Allah, every stage of growth and the secretion of this hormone are controlled. This, once again, proves the knowledge and might in the creation of every point of the human body.