Homeostasis and Immunity Overview

Life is dependent upon availability of an energy source and raw materials that are used in the basic enzyme-controlled biochemical processes of living organisms. These biochemical processes occur within a narrow range of conditions. Because organisms are continually exposed to changes in their external and internal environments, they must continually monitor and respond to these changes. Responses to change can range in complexity from simple activation of a cell chemical process to elaborate learned behavior. The result of these responses is called homeostasis, a “dynamic equilibrium” or “steady state” which keeps the internal environment within certain limits.

Organisms have a diversity of homeostatic feedback mechanisms that detect deviations from the normal state and take corrective actions to return their systems to the normal range. These mechanisms maintain the physical and chemical aspects of the internal environment within narrow limits that are favorable for cell activities. Failure of these control mechanism can result in disease or even death.

Human Body Systems


How do enzymes maintain and regulate body processes?

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Factors Influencing Enzyme Action

Temperature, pH, enzyme concentration, substrate concentration, and the presence of inhibitors or activators all have an effect on enzyme function.

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The Immune System and Immune Response

How does immune system defend our body?

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Types of Immunity

How do we describe the components and function of a vaccine?

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Human Immune System Disorder

How can we discuss immune system disorder and ways to prevent them?

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Feedback Mechanism

How does feedback mechanism affect the survival of organism?

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