Flashcards in 5.3 Homeostasis and thermoregulation Deck (34):
what is homeostasis?
process of maintaining our internal environment within narrow limits. Dynamic equilibrium
why is homeostasis important?
chemical reactions must take place within the body and they can only take place if conditions are right
what conditions must be maintained?
what systems do organisms use to monitor and respond to changes from the steady state of the body?
chemical and electrical systems
what do chemoreceptors detect?
what do baroreceptors detect?
what do thermoreceptors detect?
what is an effector of chemoreceptors and why?
push blood containing CO2 to lungs getting rid of carbonic acid and restoring pH balance
what is the baroreceptors effector and why?
initiates decrease when a rise is detected by baroreceptors
receptors are important in homeostasis in detecting what?
changes to internal and external environment
what is convection?
transfer of heat in a gas or liquid by upward movement of warm air or liquid
what is conduction?
transfer of heat from a warmer solid object to a cooler one in direct contact
what is radiation?
transfer of heat as infrared rays
what is evaporation?
when liquid changes to a gas and has a cooling effect
what do ectotherms use to warm their bodies and core temperature?
what organisms do ectotherms include?
many ectotherms in water don't need to thermoregulate, why?
high heat capacity of water means the temp of their environment doesn't fluctuate much
why do ectotherms need to warm to a specific temperature?
need to warm to a temp when metabolic reactions happen fast enough to be active e.g. to catch prey
one behavioural adaptation of ectotherms is to lay in the sun and orientate their body why?
increase sa exposed to sun to take in as much heat as possible
give an example of an ectotherm displaying the behavioural adaptation of laying in the sun and orientating their body:
bask in the sun for long periods in other to get warm enough to move fast and hunt
how do insects show the ectotherms behavioural adaptation of using the sun to warm?
spread wings to increase sa to take in heat in order to get warm enough to fly
(behavioural) some ectotherms press their bodies against warm ground, why?
heat from conduction
(behavioural) moths and butterfly's do what in order to warm their muscles to take flight?
vibrate their wings
what behavioural adaptations do ectotherms have to decrease core temp?
shelter in shade
press against cold rocks
orientate so minimum area is exposed to sun
go into water
what is a physiological adaptation some ectotherms have regarding their colour?
dark colours absorb more radiation
so lizards in colder climates tend to be darker to gain more heat
(physiological) some ectotherms alter their heart rate in order to do what?
increase or decrease metabolic rate in order to regulate temperature
(endotherms) the hypothalamus detects temperature changes in what?
(endotherms) temperature receptors in the skin detect changes in what?
what do endotherms rely upon to warm their bodies and maintain a stable temperature?
what behavioural adaptations do endotherms share with ectotherms?
bask in the sun
press themselves against warm surfaces (conduction)
go in water to cool
what additional behavioural adaptations do humans (endotherms) have to stay warm?
build homes for shelter
heating systems to warm their house
what are the three physiological cooling responses endotherms use?
reducing insulating effect of hair
how do endotherms use vasodilation? (cooling)
arterioles at skin surface dilate in warm temperatures
shunt vessels constrict forcing blood through capillary networks near skins surface, causing skin to cool due to increase radiation