Human reproductive behavior, as well as any other human behavior, can be divine, good, useful, unnecessary, unhelpful or downright evil, but it always has a physiological basis, whether or not it contributes to the survival of the species. This review book is often highly personal, with stories drawn from the experience of the author in order to illustrate physiological processes, however, it is completely outside the scope of this book to either condone or condemn any physiological function in the human body. Throughout this book recurs a story about an Intrepid Expeditioner. The Intrepid Expeditioner is you who seeks knowledge, understanding and wisdom. May you be truly blessed as you travel, and may the places you visit be blessed by your expeditions.
Homeostasis is the fundamental concept in Physiology.
Simply, it means that the body tries to stick to what it knows to keep itself working. If the body is used to having a certain amount of water in each cell and this is slightly decreased, the healthy individual consumes more water and eliminates less until the cells are again adequately hydrated. The first three answers are similar in that there is a clear lack perceived at the cellular level which the cell, the organ and ultimately the whole body works together to correct. The final answer is not so clear, because it brings into play the parallel drive of the human body to reproduce. Answer d does not describe homeostasis because reproduction or its contemplation gives no immediate survival benefit to the young man.