Physiology Supplement

Physiology

The study of the mechanisms by which the body functions.

Homeostasis

The maintenance of a constant internal environment in the body.

Reflex

A built-in response to a stimulus, which involves a series of steps from stimulus detection to response generation.

Negative Feedback

A response that opposes the stimulus; it is the most common form of feedback in the body.

Positive Feedback

A response that increases the stimulus further.

Acclimatization

Enhancement of response due to prolonged exposure to environmental changes.

Biorhythms

Internally driven cycles that affect physiological processes.

Extracellular fluid (ECF)

Fluid that is contained within the skin but external to cells; makes up about 1/3 of total body water.

Intracellular fluid (ICF)

Fluid found within cell membranes; makes up 2/3 of total body water.

Alimentary canal

The major organs of the digestive system including mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus.

Absorption

The passage of particles from the external environment to the internal environment.

Liver functions

Metabolism of nutrients, storage of vitamins and minerals, production of plasma proteins, and detoxification of blood.

Glycogenesis

The process of converting glucose into glycogen for storage in the liver and muscle.

Lipogenesis

The conversion of glucose and other substrates into fatty acids for storage.

Glycogenolysis

The breakdown of glycogen into glucose for release into the blood.

Glucagon

A hormone that increases blood glucose levels by stimulating glycogenolysis and gluconeogenesis.

Insulin

A hormone that decreases blood glucose levels by promoting glucose uptake by cells.

Type I Diabetes Mellitus

Insulin-dependent diabetes resulting from the loss of B-cells in the pancreas.

Type II Diabetes Mellitus

Insulin-independent diabetes characterized by insulin resistance.

Chemical Digestion

The hydrolysis of polymers into monomers for absorption.

Salivary Amylase

An enzyme that begins the digestion of carbohydrates in the mouth.

Pepsin

An enzyme that breaks down proteins in the stomach.

Micelles

Structures formed by the association of bile salts with breakdown products of fat, facilitating lipid absorption.

Hydrolysis

The chemical process of breaking down compounds by addition of water.

Stimulus

Any detectable change in the environment that triggers a reflex response.