Exam 3 Flashcards
(226 cards)
Who coined the term “homeostasis”- A condition which may vary, but which is relatively constant
Walter B. Cannon
Convection
Type of heat transfer- circulation or movement of fluid or gas (eg wind, heating of water on a stove)
Radiation
Type of heat transfer- energy emitted by one source and absorbed by another (sunlight)
Evaporation
Type of heat transfer- conversion of liquid to gas (sweating, panting)
Conduction
Type of heat transfer- energy transfer along temperature gradient within or between bodies (bathing). Touching. Two things of different temps touch each other, temperatures start moving toward each other and meet in the middle
high surface area to volume ratio makes heat transfer within environment efficient and rapid when you have a high surface-to-volume ratio in your object. so want smaller object. 2:1 surface area to volume is preferable to 1:2 surface area to volume for communication outside of the cell
true
T or F Elephants consume much less O2 per kg than shrews
T. heat/energy produced by tiny things is lost pretty rapidly. elephants don’t lose a lot of energy to the environment, they are pretty well self contained
mammals and birds endotherms or ectotherms
endotherms.
animals whose temperatures are regulated by behavior AND internal metabolism (physiology). name some types of physiological thermoregulation
endotherms- shivering, piloerection (hair standing on end) panting, sweating, brown fat metabolism, seasonal hair growth/loss
T or F all animals display behavioral efforts to regulate temperature. Name some types of behavioral thermoregulation
T. ectotherms do this exclusively, no physiological regulation.
Behavioral thermoregulation-
Basking in reptiles
Posture, lowering or increasing surface area
Bathing in water
Urine washing (monkeys)
Huddling (rat pups)
cells in what area of the hypothalamus change firing rate with increases or decreases in temperature?
Preoptic area
physiological responses to cold
increased thyroid activity (metabolism)
metabolism of brown fat
constriction of cutaneous blood vessels
shivering of muscles
physiological responses to heat
increased respiration
perspiration
dilation of cutaneous blood vessels
Prominent thermoregulatory structure, place with the finest set zone
Hypothalamus. no single thermostat in nervous system, brainstem and spinal cord also thermoregulate
brown adipose tissue function
gets metabolized to generate heat around the body
who are the most significant evaporators? (best distance runners in animal kingdom) what caused this adaptation?
Humans! persistence running caused this adaptation
piloerection function
creates insulation by trapping air. vestigial in humans
countercurrent heat exchange in nasal veins and testicles. what is it and why does it exist?
Neural and testicular tissue is damaged at lower temperatures than other body tissues, want to avoid damage of hot blood in brain and balls. cold blood in nasal veins surrounds arterial blood on its way to the brain. similar in balls
Although there are significant metabolic costs of having the capability of thermoregulation, why do endotherms have an advantage over ectotherms?
expanded niche! endotherms can exist in a much larger range of environments
Number phases following infection: Body temperature increases. Set point increases, causing a cold feeling. Body temp decreases. When infection is neutralized, set point returns to original, feel hot
2,1,4,3
How do ectotherms fight off an infection if their temperature is not internally regulated?
Behavioral fever. Use behavior to change environmental temperature and generate fever (go under light in cage)
Huddling is an example of what form of thermal energy regulation/exchange
conduction. Also minimizing surface area exposed to outside cold temperature
What is the function of the brood patch in birds?
allows for direct conduction of heat. Mostly directed toward developing babies
How do some ectotherms survive subzero body temperatures?
Have an antifreeze protein in their blood. Fish blood protein used in ice cream to keep it smooth instead of crystallized