U3: Lesson 3.2 - Negative Feedback & Positive Feedback Loop

Homeostasis

The process by which a constant internal environment is maintained despite changes in external conditions.

Negative Feedback Loop

A control mechanism that counteracts a change, bringing a system back to its set point.

Positive Feedback Loop

A control mechanism that enhances or increases the change or output; it pushes the system away from its starting state.

Thermoreceptors

Sensory receptors that detect changes in temperature.

Hypothalamus

The control center in the brain that regulates body temperature and other homeostatic functions.

Insulin

A hormone produced by pancreatic beta cells that lowers blood glucose levels.

Glucagon

A hormone produced by pancreatic alpha cells that raises blood glucose levels.

Renin-Angiotensin-Aldosterone System (RAAS)

A hormone system that regulates blood pressure and fluid balance in the body.

Parathyroid Hormone (PTH)

A hormone released by the parathyroid glands that increases blood calcium levels.

Calcitonin

A hormone released by the thyroid gland that decreases blood calcium levels.

Vasoconstriction

The narrowing of blood vessels which increases blood pressure.

Vasodilation

The widening of blood vessels which decreases blood pressure.

Shivering

Involuntary muscle contractions that generate heat to raise body temperature.

Osteoblasts

Cells that build up bone and regulate calcium levels in the body.

Osteoclasts

Cells that break down bone tissue, releasing calcium into the bloodstream.

Hyperglycemia

A condition characterized by an excessive amount of glucose in the blood.

Hypoglycemia

A condition characterized by abnormally low blood glucose levels.

Homeostatic Mechanism

Processes that maintain the stability of the body's internal environment.

Effectors

Organs or cells that act in response to signals from the control center to restore homeostasis.

ADH (Antidiuretic Hormone)

A hormone that increases water reabsorption in the kidneys, raising blood pressure.

Acidosis

A condition characterized by an abnormal increase in acidity of the body fluids.

Alkalosis

A condition characterized by an abnormal decrease in acidity of the body fluids.

Electrolytes

Minerals in body fluids that carry an electric charge and are vital for many bodily functions.

Buffers

Substances that help maintain the pH balance in the body by neutralizing acids and bases.

Metabolism

The set of life-sustaining chemical reactions that convert food into energy.

Oxidation

A chemical reaction that involves the loss of electrons or an increase in oxidation state by a molecule.

Reduction

A chemical reaction that involves the gain of electrons or a decrease in oxidation state by a molecule.

Aerobic Respiration

The process of producing cellular energy with oxygen.

Anaerobic Respiration

The process of producing cellular energy without oxygen.

Homeostatic Set Point

The ideal physiological level that the body attempts to maintain for various functions.