A PERFECT ARMY SET ON ITS GOAL
such a thing occurs is clear proof that the cell is under the direction of a supreme intelligence. Moreover, that these cells are exactly at the proper place, (that is, in the seminiferous tubules where the sperm develop,) and that they have exactly the requisite qualities (for example, they are larger than the spermatids) is one of the millions of proofs of the perfect design of the human body. God has placed every one of the approximately 100 trillion cells that make up the human body in its proper place; He has given to each one the qualities it needs; and He has given each one the instinct to do its work perfectly. As we are told in the Qur'an: ... There is no creature He does not hold by the forelock. My Lord is on a Straight Path. (Qur'an, 11: 56)
An Interdependent System In the preceding section we spoke about the role of the Sertoli cells in the transformation of the spermatids into the sperm. What is the physical force that activates these cells and makes them know their duty to nourish the spermatids and monitor their development? The impetus which makes the Sertoli cells perform their function comes from the follicle-stimulating hormone (FSH), which was mentioned in the earlier section. This hormone is secreted from the anterior pituitary gland and stimulates the Sertoli cells. If this hormone is not produced or fails to reach the relevant area, sperm cannot be produced. When the Sertoli cells receive the stimulation, they begin to secrete a hormone called oestrogen, which is indispensable for sperm production. Another kind of cell that influences sperm production is called the "Leydig" cell; it is found between the seminiferous tubules. These cells produce another hormone required for sperm to develop. The LH (luteinizing hormone) is secreted from the anterior pituitary gland and stimulates the Leydig cells. Then, these cells begin to produce the testosterone hormone. Testosterone is the hormone which assures the growth of the reproductive organs, the development of various glands of these organs and the development of the male sexual characteristics; it is, moreover, the most important hormone in the production of sperm. 31