Temperature Control

Front 1

Survival in cold environments
Antifreeze

Back 1

ectotherms: some fish
body fluids: drop below freezing, but remain fluid
antifreeze compounds

Front 2

Survival in cold environments
Freezing

Back 2

ectotherms: some lissamphibia
body temp: below freezing, but >-10C
ice crystals: only outside of body (body= 34-48%)
breathing heart: slow/stop (cellular metabolism slows)

Front 3

Survival in cold environments
Insulation

Back 3

endotherms: hair, feathers, blubber
reduce conductive/convective heat loss
inhabit coldest habitats on Earth (ex. -70C)

Front 4

Survival in cold environments
Countercurrent exchangers

Back 4

ectotherms and endotherms
regional heterothermy
ex. in billed fishes & tuna
ex. in flippers of seals & leatherback turtles

Front 5

Survival in cold environments
regional heterothermy

Back 5

parts of body vary in temperatures

Front 6

Survival in cold environments
antifreeze compounds

Back 6

glycoproteins & polypeptides

Front 7

Survival in cold environments
Torpor and hibernation

Back 7

ectotherm and endotherm
body temperature drops: reduces metabolic requirement
endotherms: hummingbirds, chickadees, ground squirrels, deep torpor, periodic arousal
ectotherms: lissamphibians, squamates, turtles

Front 8

Survival in cold environments
deep torpor

Back 8

only feasible for small endotherms

Front 9

Survival in cold environments
periodic arousal

Back 9

required during prolonged torpor

Front 10

Survival in hot and dry environments

Back 10

thermal stressed compounded by water stress
refuges and behavior
relaxation of homeostasis
insulation and reduced basal metabolic rate

Front 11

Survival in hot and dry environments
Refuges and behavior

Back 11

ectotherm and endotherm
burrows and shelters: cooler & more humid
activity: refuge to refuge, restricted diurnally or seasonally (estivation)

Front 12

Survival in hot and dry environments
Relaxation of homeostasis

Back 12

tolerate high temps: conserve water
regional heterothermy
critical areas: cool or slow heating, ex. brain of African ungulates
stored wastes: conserve water

Front 13

Survival in hot and dry environments
Insulation and reduced basal metabolic rate (BMR)

Back 13

endotherm
insulation: reduces heat gain by convection, conduction, ect
reduced BMR: reduces metabolic heat load

Front 14

Thermoregulation and critical temps
ectothermy

Back 14

reliance on environmental thermal energy
activity temperature range (ATR), use behavioral and physiological regulation, often maintain narrow range (homeotherm) and "warm," upper and lower lethal temps

Front 15

Thermoregulation and critical temps
ectothermy
activity temperature range (ATR)

Back 15

range of temps where normal activity may occur
limits sustainable conditions of species

Front 16

Thermoregulation and critical temps
ectothermy
use behavioral and physiological regulation

Back 16

ex. color change, physical orientation, shelter, blood vessel & heart flow

Front 17

Thermoregulation and critical temps
ectothermy
often maintain narrow range (homeotherm) and "warm"

Back 17

invalidates terms like "poikilotherm" & "cold-blooded"

Front 18

Thermoregulation and critical temps
ectothermy
upper and lower lethal temps

Back 18

often well outside ATR

Front 19

Thermoregulation and critical temps
endothermy

Back 19

primary reliance on metabolic heat
zone of thermal tolerance, thermoneutral zone, lower critical temperature, lower lethal temperature, upper critical temperature, upper lethal temperature

Front 20

Thermoregulation and critical temps
endothermy
zone of thermal tolerance

Back 20

t1 to t4
range in which body temps can be maintained
some homeotherms and heterotherms

Front 21

Thermoregulation and critical temps
endothermy
thermoneutral zone

Back 21

t2 to t3
basal metabolic rate is sufficient for heat production

Front 22

Thermoregulation and critical temps
endothermy
lower critical temperature

Back 22

metabolic rate increases to maintain body temp

Front 23

Thermoregulation and critical temps
endothermy
lower lethal temperature

Back 23

animal dies of hypothermia (cascading effect)

Front 24

Thermoregulation and critical temps
endothermy
upper critical temperature

Back 24

animal must use evaporation to maintain temp

Front 25

Thermoregulation and critical temps
endothermy
upper lethal temperature

Back 25

animal dies of hyperthermia (cascading effect)

Front 26

Survival in cold environments
super-cooling

Back 26

ectotherms: some fishes & amphibians
body fluids: drop below freezing, but remain fluid
avoid nucleating crystals: ice doesn't form

Front 27

Simple energy budget

Back 27

I - E = (Mb + Ma) +B

Front 28

I - E = (MB + MA) + B

Back 28

I= energy ingested
E= excreted energy
Mb= basal metabolic rate (BMR)
Ma= active metabolic rate
B= energy converted into biomass (growth and reporduction

Front 29

Simple energy budget
Body temp

Back 29

influences Mb and Ma
can also influence I, E, and B

Front 30

Simple energy budget
Body size

Back 30

influences Mb
the larger the organism the lower the Mb

Front 31

Water balance and energy interactions

Back 31

water is derived from free and metabolic water
water loss = nutrient conversion, excretion, evaporation
many verts rely on water from food and metabolism
ex. desert turtles

Front 32

free water

Back 32

direct from environment or food

Front 33

metabolic water

Back 33

from metabolism
ex. 1g of fat =1.07 g H2O, 1g carbo =.56 H2O