homeostasis

homeostasis

organisms strive to maintain a stable internal environment

• ph

• solute concentration

• temp

• glucose

• fats, etc

too low temp

• cause cell membrane fluidity problems

• ice can from

• enzymes fail to function correctly

temp too high

• proteins denature

• enzymes fail to function correctly

negative feedback loops

• set point

• senor

• integrator

• effector

set point

level the homeostatic system is attempting to stick to

sensor

structure that senses some aspect of the external or internal environement

integrator

part of the nervous system that evaluates sensory information and “decides” if a response is necessary to achieve homeostasis

• in vertebrates the hypothalamus

effector

any structure that helps to restore the desired internal condition

when does negative feedback occur

• when the regulatory system makes a change in the opposite direction to a change in internal conditions

• or the products inhibit the process

radiation

transfer of heat energy through the atmosphere through the atmosphere electromagnetic _________

evaportation

goes from liquid to gas uses your heat

conduction

direct transfer

convection

essentially conduction to a moving substance (a fluid or gas)

what do organisms use to bring the system back to the set point

• physiological

• behavioral

these are effectors

behavioral responses

movement, seeking shade, licking limbs

physiological responses

• circulatory adaptations

• adjusting metabolic heat production

two physiological adaptations

• countercurrent heat exchanges

• vasodilation/constriction for heat loss