2 - Homeostasis

Abstract

A central principle of human function is that we maintain relatively constant conditions inside our body. Unless our body is able to maintain about the same temperature, pressure, oxygen level, acidity, moisture, and so on, all the time, our cells cannot function properly. We will get sick and we will die unless proper conditions are restored. Any of the functions of the organs and systems of the body we will study throughout the rest of this book are all explained by their impact on maintaining relatively constant conditions inside our body. This concept of internal stability is called homeostasis and is the focus of this chapter. After studying this chapter, you will have a basic understanding of homeostatic balance and how it is maintained in the body. Your understanding will deepen as you move forward in your studies, as you encounter example after example of body functions maintaining constantly high oxygen levels, normal fluid pressure, low waste levels, high nutrient levels, and so on. You will also encounter examples of disorders that occur when organs fail and our body cannot maintain normal internal conditions. •