Homeostasis

Question	Answer
Homeostasis definition:	The maintenance of a constant internal environment in organisms
Negative feedback mechanism definition:	A change from the normal level is detected and triggers a response which reverses the change and restores the norm
Stimulus:	A change in the environment
Receptor:	Detects any deviation from a set point
Coordinator	Coordinates information from receptors
Effector	Brings about changes to return a system to a set point
Response	a change brought about by an effector
Ectotherm:	Animals such as reptiles which gain their body heat from the environment
Endotherm:	Animals, such as birds and mammals which generate most of their heat from respiration
Regulation of body temperature of ectotherms:	Exposure to sun, sheltering in the shade, gaining warmth from the ground, generating metabolic heat from respiration showing colour variations
Metabolic activities when the blood temperature of endotherms fall below normal:	Vasoconstriction Hair erector muscles contract Shivering - skeletal muscles Brown/White fat Hormone - adrenaline Behavioural mechanisms e.g putting on clothes etc.
Metabolic activities if the blood temperature in endotherms reaches above normal:	Vasodilation Hair erector muscles dilate Sweating Behavioural mechanisms e.g sitting in the shade

Resource summary

	Created by Elena Cade about 8 years ago