Thermoregulation Feedback Loops

Thermoregulation

The process by which the body maintains a stable internal temperature (around 37°C) despite external temperature changes.

Homeostasis

The maintenance of a constant internal environment within the body, achieved through feedback mechanisms like thermoregulation.

Negative Feedback Loop

A control mechanism that counteracts a change in the body’s internal conditions to restore balance.

Stimulus (in thermoregulation)

A change in body temperature (increase or decrease) that triggers the feedback loop.

Receptor (Sensor)

Detects temperature changes; includes thermoreceptors in the skin and hypothalamus.

Control Center

The hypothalamus; compares the actual temperature to the set point and activates appropriate effectors.

Effector

Organs or tissues that carry out responses to correct temperature changes (e.g., sweat glands, blood vessels, muscles).

Response

The physiological action that restores body temperature to the normal range.

Vasodilation

Widening of blood vessels to increase blood flow to the skin and promote heat loss when body temperature is high.

Vasoconstriction

Narrowing of blood vessels to reduce blood flow to the skin and conserve heat when body temperature is low.

Sweating

Secretion of sweat by glands; evaporation cools the body to lower temperature.

Shivering

Rapid muscle contractions that generate heat to raise body temperature.

Piloerection

Hair stands up ("goosebumps") to trap air near the skin and reduce heat loss; minor effect in humans.

Heat Gain Mechanisms

Actions that increase body temperature, such as shivering, vasoconstriction, and increased metabolism.

Heat Loss Mechanisms

Actions that decrease body temperature, such as sweating and vasodilation.

Hypothermia

A dangerous drop in body temperature due to prolonged cold exposure or failure of heat-gain mechanisms.

Hyperthermia

A dangerously high body temperature due to failed cooling mechanisms or excessive heat exposure.

Set Point (for temperature)

The normal core temperature regulated by the hypothalamus, approximately 37°C (98.6°F).