Thermoregulation Flashcards
What is a thermoregulation?
A process by which animals maintain a body temperature within an accepted range
What is a thermoconformer?
As the ambient (outside temperature) increases, the internal body temperature increases
What would happen if humans could not thermoregulate?
Proteins would denature (lose shape and no longer function)
The fluidity of cells membranes can change (membrane changes form)
Some biochemical reactions can change their rates
What is endothermy and where does the heat generate?
Endo(inside body)thermic animals generate heat from metabolism
Why is ectothermy and where doe they get they heat?
Ecto(outside)thermic animals gain heat from external sources
Who requires more energy to maintain body heat and why?
Thermoregulators/endothermic animals require more energy to maintain because the range from temperature to body heat can increase making maintain heat difficult.
Ectotherms tolerate _______ variation in internal temperature while endotherms are active at a _______ range of external temperatures.
- Wide
2. Narrow
What is a poikilotherm?
Body temperature changes with its environment.
What is a homeotherm?
Body temperature remains constant
Name two endotherms that are poikilotherms. Explain why this is the case.
Bats- they sleep during the winter and lower their body temperatures to slow metabolic rates.
Hummingbirds- migrate during the winter, but are short term poikilotherms. Will drop body temperature for a short period of time.
What are the four types of heat exchange in organisms? Define each
Radiation- heat from sun or other organisms
Evaporation- moisture from nose or mouth or sweat glands. ONLY AS GOOD AS HYDRATION
Conduction- contact with physical object
Convection- contact is moving (wind blowing)
Heat is regulated in mammals often in what body system?
Integumentary system
What are the five strategies to help animals thermoregulate?
Insulation Circulatory adaptions (adjusting blood flow) Cooling by evaporative heat loss Behavioral responses Adjusting metabolic heat production
What are four types types of insulation?
Skin
Feathers (trap body heat under feathers to insulate)
Fur (air blanket to insulate body)
Blubber (fat under skin all over body)
Many endotherms and some ectotherms can alter the amount of blood flowing between the ______ body core and their _______.
- Body core
2. Skin
What is vasodilation?
Blood flow in the skin increases, facilitating heat loss.
What is vasoconstriction?
Blood flow in the skin decreases, lowering heat loss.
Explain countercurrent heat exchange.
Heat is transferred from arteries (away) to veins (visit). The blood vessels must be right next to each other. The blood vessels must flowing in opposite directions. This will lead to heat loss. This is an example of both conduction and convection.
What is the benefit of countercurrent heat exchange?
Very little heat is lost to the surface
What are some examples of cooling by evaporative heat loss?
Sweating- sweat glands to evaporate
Panting- use saliva, water evaporates off tongue
Bathing- some evaporation, heat from body turns water into gas
Urihydreosis- urine down legs with water, heat from body turns urine into gas
Gular flutter- open mouth, area under beak filled with blood vessels. Moisture turns body heat into evaporation
What are some behavioral responses to increase/decrease heat exchange?
Group interaction (huddling)
Postures (turning into or away from wind)
Body shape (shape)
Food and beverage
Hibernation (slow metabolism and decrease body temperature)
Migration (move somewhere warm with fresh food)
What type of food generates the most heat?
Proteins
What is the correlation between surface area to volume ratio?
The higher the ratio, more likely to lose heat
SA/V
Thermogenesis is increased by the activity such as ________ or _________.
- Moving
2. Shivering
What is non-shivering thermogenesis?
Hormones (thermogen) causes the mitochondria to increase their metabolic activity.
What does thermogen do to the body?
Produce heat, but uncoupled from the production of ATP.
Do humans have brown fat?
Yes! It is thought that humans have it surrounding the neck and is active during cold stress.
