Define Homeostasis and Feedback - Biology

The target value or narrow range for a regulated variable. Like a thermostat setting - the ideal value to maintain.

A measurable internal condition kept near a set point. Examples include temperature, pH, and glucose levels.

Homeostatic control of internal body temperature. Maintains optimal body temperature for enzyme function.

Maintenance of a stable internal environment despite external change. Keeps vital conditions like temperature and pH stable.

A measurable internal condition kept near a set point. Examples include temperature, pH, and glucose levels.

A change in a regulated variable that triggers a response. Acts as the initial disturbance that starts the feedback loop.

A structure that detects change in a regulated variable. Like a thermometer - monitors conditions continuously.

Blood $CO_2$ concentration (or blood pH). High $CO_2$ triggers increased breathing rate.

Regulation of blood glucose concentration near a set point. Keeps blood sugar stable for cellular energy needs.

The component that compares input to the set point and directs output. The 'brain' that processes information and makes decisions.

To intensify change until an endpoint stops the loop. They accelerate processes until completion or limit.

To counteract deviations and stabilize internal conditions. They reverse changes to restore normal conditions.

Normal range (acceptable range). Defines acceptable variation without triggering responses.

Stimulus → receptor → control center → effector → response. Shows how information flows through the control system.

Small fluctuations around a set point while remaining stable overall. Constant adjustments maintain average stability over time.

Positive feedback. It accelerates until reaching a natural stopping point.

Negative feedback. It stabilizes conditions rather than amplifying changes.

A response that amplifies the initial change, moving away from set point. Accelerates change rather than stopping it.

A response that reduces the initial change and returns toward set point. Like a thermostat - opposes change to maintain stability.

A regulatory process in which a system’s output influences the system. Creates loops where output affects future input.

A muscle, gland, or organ that carries out the corrective response. The 'worker' that actually makes the physical changes.

Negative stabilizes near set point; positive amplifies until an endpoint. Negative maintains stability; positive drives completion.

Skeletal muscles (shivering) and skin blood vessels (vasoconstriction). Both promote heat conservation and generation.

Sweat glands and skin blood vessels (vasodilation). Both promote heat loss through different mechanisms.

Hypothalamus. Brain region that processes temperature information.

Set points can shift within limits (for example, fever alters temperature). Set points can be adjusted based on physiological needs.

They maintain internal conditions required for enzyme and cell function. Stable conditions are essential for cellular processes.

Response. The actual change produced by effector activation.

Information sent from receptors to the control center. Sensory data about current conditions being monitored.