Homeostatic Controls and Organ Systems

These flashcards cover key concepts regarding homeostatic controls, bodily systems, their functions, and important definitions for understanding maintaining a stable internal environment.

Homeostasis

The ability of the body to maintain relatively stable internal conditions in spite of changes in the outside environment.

Receptor

A sensor that detects a change in the variable.

Control Center

The structure that receives information about the variable, compares it to the homeostatic value, and determines a response.

Afferent Pathway

The pathway that takes information about the variable to the control center.

Efferent Pathway

The pathway that takes information from the control center to the structure(s) that carries out the response.

Effector

A structure that carries out the response.

Set Point

The level (or range of levels) at which a variable is to be maintained; the homeostatic value.

Negative feedback mechanism

A series of steps that causes a variable to change in the direction opposite to that of the initial change.

Positive feedback mechanism

Response enhances or exaggerates the original stimulus, causing greater imbalance.

Metabolism

All chemical reactions that occur in cells; the sum of catabolism and anabolism.

Excretion

Removal of wastes from metabolism and digestion.

Digestion

Breakdown of food; absorption of nutrients into blood.

Cardiovascular System

Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc.; the heart pumps blood.

Nervous System

The fast-acting control system of the body, responding to internal and external changes.

Endocrine System

Glands that secrete hormones regulating processes such as growth, reproduction, and metabolism.

Integumentary System

Forms the external body covering, protects deeper tissues, synthesizes vitamin D, and houses receptors.

Skeletal System

Protects and supports body organs and provides framework for muscle movement.

Muscular System

Allows manipulation of the environment and locomotion, maintains posture, and produces heat.

Lymphatic System

Picks up fluid leaked from blood vessels and returns it to blood; involves immunity.

Respiratory System

Keeps blood supplied with oxygen and removes carbon dioxide through gas exchange in lungs.

Digestive System

Breaks down food into absorbable units and eliminates indigestible food as feces.

Homeostatic Imbalance

Disturbances that increase risk of serious diseases and contribute to changes associated with aging.