Homeostatic Imbalance

Homeostasis is so important that most disease can be regarded as a result of its disturbance, a condition called homeostatic imbalance. As we age, our
body’s control systems become less efficient, and our internal environment becomes less and less stable. These events increase our risk for illness and produce the changes we associate with aging.

Another important source of homeostatic imbalance occurs when the usual negative feedback mechanisms are overwhelmed and destructive positive feedback mechanisms take over. Some instances of heart failure reflect this phenomenon.

Examples of homeostatic imbalance are provided throughout this book to enhance your understanding of normal physiological mechanisms. These homeostatic imbalance sections are preceded by the symbol jjfEfj to alert you to the fact that an abnormal condition is being described.