TEMPERATURE REGULATION Flashcards
(22 cards)
what is sensitivity and feedback used for
to keep internal milieu in a set range.
what is the Q10 effect
this is a measure of how the rate of reaction increases due to a 10º increase.
if rate doubles Q10 = 2
poikilotherm
body temp varies
homeotherm
body temp is stable
endotherm
primary source of heat is metabolic.
have high MR
ectotherm
primary source of heat is from environment
low MR and envrionment determines body temp
what is the thermoneutral zone
where no work needs to be done to maintain temp
why do endotherms produce a lot of heat
endotherms have “leakier” membranes, need to maintain concentration gradients. these biochemical processes generate heat which can be used for regulation
types of heat exchange
conduction: transfer of thermal motion
convection: transfer of heat from a fluid
radiation: transfer from non-touching objects
evaporation: removal of heat when liquid evaporates
ice to liquid water
100 cal/g
liquid to gas water
580 cal/g
behavioural mechanisms
- insulation
- heat windows
- countercurrent heat exchange
- sweating
- avoidance
- postural changes
- hibernation/torpor
ficks equation
Q = (daP)/l
Q usually proportional to SA/l
animals without specialised respiratory surfaces need to be
thin, small or have high SA with low MR as less O2 is taken in
what are trachae
hollow tube system found in insects and myropods. limited transport capacity. ventilation through body compression of air sacs
lungs inverterbrates
book lungs
lungs amphibians
intermediate step. positive pressure push air into lungs
lungs mammals
negative pressure sucks air in. residual air always present.
vital capacity = inital volume taken in.
lungs birds
-ve pressure 2 step process.
air sacs fill and exhaling squeezes air sac so air flows into the lungs. More efficient no residual space in lung
human structure of lung
sponge like. air comes from: trachea bronchus bronchiole alveoli
gas exchange occurs only in alveoli. Ciliaremove dust. Surface tension is opposed by proteins and lipids so that inhalation can expand.
increase in fluid in alveoli makes diffusion harder “winded”
what is the equation of signalling when to breath
CO2 + H2O = H2CO3 = HCO3- + H+
how is breathing signalled
when CO2 levels are high, this signals breathing.
Hyperventilation decreases CO2 levels before holding your breath. Therefore later, the trigger point will not be reached before black out point (no O2) and black-out will occur
