Homeostasis

Homeostasis

The ability to maintain a relatively stable internal environment in an ever-changing outside environment.

Ectotherms

Animals that rely on external sources of heat for temperature regulation.

Endotherms

Animals that regulate their temperature by producing heat metabolically or by actively losing heat.

Basal Metabolic Rate (BMR)

The metabolic rate of a resting animal at a temperature within the thermoneutral zone.

Negative Feedback

A process where the output of a control system causes the effector to reduce or reverse the original stimulus.

Positive Feedback

A process where the output intensifies the original stimulus, amplifying the response.

Thermoregulation

The physiological process of maintaining body temperature within a normal range despite external temperature fluctuations.

Hypothalamus

The major center of temperature regulation in vertebrates, acting as a thermostat.

Sensor

The component of a regulatory system that monitors the environment and provides feedback information.

Control Center

The part of a regulatory system that processes information and issues commands to effectors.

Effector

The component of a regulatory system that provides the means to respond to stimuli and effect changes in the internal environment.

Thermogenin

A protein in brown fat that causes heat release by uncoupling proton-motive force from ATP production.

Pyrogens

Substances that can cause a rise in body temperature by raising the set point for metabolic heat production.

Conduction

The transfer of heat by direct contact.

Evaporation

The process of heat transfer through the evaporation of water from a surface.

Countercurrent Heat Exchange

A mechanism that reduces heat loss by allowing warm arterial blood to heat up cooler venous blood.