You’ve seen homeostasis defined as a condition in which the body’s internal environment remains relatively stable. The body’s ability to maintain homeostasis gives it tremendous healing power and a remarkable resistance to abuse. The physiological processes responsible for maintaining homeostasis are in large part also responsible for your good health.
For most people, lifelong good health is not something that happens effortlessly. The many factors in this balance called health include the following:
• The environment and your own behavior.
• Your genetic makeup.
• The air you breathe, the food you eat, and even the thoughts you think.
The way you live your life can either support or interfere with your body’s ability to maintain homeostasis and recover from the inevitable stresses life throws your way.
Many diseases are the result of years of poor health behavior that interferes with the body’s natural drive to maintain homeostasis. An obvious example is smoking-related illness. Smoking tobacco exposes sensitive lung tissue to a multitude of chemicals that cause cancer and damage the lung’s ability to repair itself. Because diseases such as emphysema and lung cancer are difficult to treat and are very rarely cured, it is much wiser to quit smoking—or never start—than to hope a doctor can “fix” you once you are diagnosed with a lung dis- ease. Developing a lifestyle that works with, rather than against, your body’s homeostatic processes helps you maximize your personal potential for optimal health and well-being.
As long as all of the body’s controlled conditions remain within certain narrow limits, body cells function efficiently, homeostasis is maintained, and the body stays healthy. Should one or more components of the body lose their ability to contribute to homeostasis, however, the normal balance among all of the body’s processes may be disturbed. If the homeostatic imbalance is moderate, a disorder or disease may occur; if it is severe, death may result.
A disorder is any abnormality of structure or function. Disease is a more specific term for an illness characterized by a recognizable set of signs and symptoms. A local disease affects one part or a limited region of the body (for example, a sinus infection); a systemic disease affects either the entire body or several parts of it (for example, influ- enza). Diseases alter body structures and functions in characteristic ways. A person with a disease may experience symptoms, subjective changes in body functions that are not apparent to an observer. Examples of symptoms are headache, nausea, and anxiety. Objective changes that a clinician can observe and measure are called signs. Signs of disease can be either anatomical, such as swelling or a rash, or physiological, such as fever, high blood pressure, or paralysis.
The science that deals with why, when, and where diseases occur and how they are transmitted among individuals in a community is known as epidemiology (ep′-i-dē-mē-OL-oˉ-jē; epi- = upon; -demi = people). Pharmacology (far′-ma-KOL-oˉ-jē; pharmac- = drug) is the science that deals with the effects and uses of drugs in the treatment of disease.
References:
Derrickson B.H. "Principles of Anatomy and Physiology"
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