Homeostasis

Homeostasis

The process of keeping the internal environment of the body fairly constant despite fluctuations in the external environment.

Feedback system

A system that maintains homeostasis involving components such as stimulus, receptor, modulator, effector, response, and feedback.

Negative feedback

A response mechanism where the body's response reduces or eliminates the stimulus, restoring a steady state.

Positive feedback

A response mechanism where the body's response reinforces or intensifies the stimulus.

Thermoregulation

The process of maintaining balance between heat production and heat loss.

Vasodilation

The increase in diameter of blood arterioles in the skin to increase blood flow to the area.

Vasoconstriction

The decrease in diameter of an arteriole to reduce blood flow to the area.

Glycogenesis

The process of converting glucose into glycogen for storage.

Glycogenolysis

The process of breaking down glycogen into glucose, raising blood glucose levels.

Gluconeogenesis

The creation of new glucose molecules from non-carbohydrate sources, such as fats and amino acids.

Hyperglycemia

Abnormally high glucose levels in the blood.

Diabetes Type 1

Early onset diabetes characterized by the destruction of beta cells leading to the absence of insulin production.

Diabetes Type 2

Late onset diabetes characterized by body cells becoming less responsive to insulin.

Piloerection

The contraction of small muscles surrounding hair follicles, causing hair to stand erect.

Thermoreceptors

Specialized sensory receptors that detect changes in temperature; they can be peripheral or central.

Core body temperature

The normal temperature range for humans, approximately 36.5°C to 37.0°C.

Glycogen

A complex carbohydrate made up of long chains of glucose molecules, stored in the liver and muscle cells.

Insulin

A hormone released by the pancreas that lowers blood glucose levels by accelerating the conversion of glucose into glycogen.

Glucagon

A hormone released by the pancreas that raises blood glucose levels by stimulating glycogenolysis and gluconeogenesis.

Adrenaline

A hormone produced by the adrenal glands that increases blood glucose levels during stress.

Cortisol

A glucocorticoid hormone from the adrenal glands that also raises blood glucose levels.