Homeostasis and Mechanisms

These flashcards cover the key vocabulary and concepts related to homeostasis, feedback mechanisms, and physiological responses essential for understanding the subject matter.

Homeostasis

The maintenance of a stable internal environment, including temperature, pH, and nutrient levels.

Homeostatic variable

The variable that a physiological system is designed to maintain near its desired level (setpoint).

Allostatic variable

A variable that is intentionally adjusted to maintain a more constant level of the homeostatic variable.

Negative feedback mechanism

A system where the stimulus causes a response that reduces or eliminates the stimulus.

Positive feedback mechanism

A system where the stimulus causes a response that enhances the stimulus.

No feedback mechanism

A situation where the stimulus causes a response, but the response does not affect the stimulus.

Effector

The muscle, gland, or organ that performs the response in a feedback mechanism.

Setpoint

The ideal or target level for a homeostatic variable.

Stimulus

A change in the internal or external environment that triggers a response.

Dysfunction

When a system, such as cellular activities, fails to function properly.

Physiological mechanisms

Processes that explain how biological functions are achieved.

Catalyst

A substance that increases the rate of a chemical reaction without undergoing any permanent change itself.

Enzyme

A protein that acts as a catalyst in biochemical reactions.

Self-limiting

A characteristic of negative feedback systems where the response eventually ceases when the variable returns to the setpoint.

Amplification

The process by which a small stimulus produces a larger response, commonly seen in positive feedback.

Behavioral response

Actions taken by an organism in response to stimuli to maintain homeostasis.