Communication and Homeostasis Keywords

Stimulus

A change in the environment that causes a response

E.g An increase  in temperature

Homeostasis

Maintenance of the internal environment in a constant state despite external changes

E.g Body Temperature

Excretion

The removal of metabolic waste from the body

E.g Sweating

Endotherms

An organism that can use internal sources of heat e.g metabolism from liver

E.g Human

Response

A change in behaviour or physiology as a result of the stimulus

E.g Sweating - after raise in temperature

Negative Feedback

A process that brings about the reversal of any change in conditions

E.g Too hot => sweat => cool down

Sensory Receptor

Something that recognises the change in conditions

E.g Baroreceptor (blood pressure)

Ectotherms

An organism that relies on external sources of heat to regulate body temperature

E.g Snake

Cell signalling

Where one cell releases a chemical that is detected by a second cell which will then respond

E.g Neuronal & Hormonal

Positive Feedback

A process that increases any change detected by receptors

E.g Childbirth

Oxytocin

A hormone involed in increasing uterine contractions

E.g childbirth

Temperature Regulation

Ensuring that temperature remains at a fairly constant rate

E.g Negative Feedback