Unit 3: Homeostasis - Negative Feedback and Diffusion -

homeostasis

the process where organ systems work to maintain (keep) a stable internal environment.

negative feedback

a response to a stimulus that keeps a variable close to a set value (it "shuts off" or "turns on" a system when it varies from a set value)

stimulus (plural: stimuli)

something that triggers a behavior or causes a reaction in an organism.

receptor

a cell or group of cells that receives stimuli

signal

a message that is sent between cells

response

an action or message as a result of a signal

diffusion

the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration

membrane

a thin sheet of tissue or layer of cells acting as a boundary, lining, or partition in an organism.

concentration gradient

The difference in the concentrations of molecules in two areas

equilibrium

the process where organ systems work to maintain (keep) a stable internal environment