Thermoregulation

Question 1

What is a thermoregulation?

Answer 1

A process by which animals maintain a body temperature within an accepted range

Question 2

What is a thermoconformer?

Answer 2

As the ambient (outside temperature) increases, the internal body temperature increases

Question 3

What would happen if humans could not thermoregulate?

Answer 3

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

Question 4

What is endothermy and where does the heat generate?

Answer 4

Endo(inside body)thermic animals generate heat from metabolism

Question 5

Why is ectothermy and where doe they get they heat?

Answer 5

Ecto(outside)thermic animals gain heat from external sources

Question 6

Who requires more energy to maintain body heat and why?

Answer 6

Thermoregulators/endothermic animals require more energy to maintain because the range from temperature to body heat can increase making maintain heat difficult.

Question 7

Ectotherms tolerate _______ variation in internal temperature while endotherms are active at a _______ range of external temperatures.

Answer 7

1. Wide

2. Narrow

Question 8

What is a poikilotherm?

Answer 8

Body temperature changes with its environment.

Question 9

What is a homeotherm?

Answer 9

Body temperature remains constant

Question 10

Name two endotherms that are poikilotherms. Explain why this is the case.

Answer 10

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.

Question 11

What are the four types of heat exchange in organisms? Define each

Answer 11

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)

Question 12

Heat is regulated in mammals often in what body system?

Answer 12

Integumentary system

Question 13

What are the five strategies to help animals thermoregulate?

Answer 13

Insulation 
Circulatory adaptions (adjusting blood flow)
Cooling by evaporative heat loss
Behavioral responses 
Adjusting metabolic heat production

Question 14

What are four types types of insulation?

Answer 14

Skin
Feathers (trap body heat under feathers to insulate)
Fur (air blanket to insulate body)
Blubber (fat under skin all over body)

Question 15

Many endotherms and some ectotherms can alter the amount of blood flowing between the ______ body core and their _______.

Answer 15

1. Body core

2. Skin

Question 16

What is vasodilation?

Answer 16

Blood flow in the skin increases, facilitating heat loss.

Question 17

What is vasoconstriction?

Answer 17

Blood flow in the skin decreases, lowering heat loss.

Question 18

Explain countercurrent heat exchange.

Answer 18

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.

Question 19

What is the benefit of countercurrent heat exchange?

Answer 19

Very little heat is lost to the surface

Question 20

What are some examples of cooling by evaporative heat loss?

Answer 20

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

Question 21

What are some behavioral responses to increase/decrease heat exchange?

Answer 21

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)

Question 22

What type of food generates the most heat?

Answer 22

Proteins

Question 23

What is the correlation between surface area to volume ratio?

Answer 23

The higher the ratio, more likely to lose heat

SA/V

Question 24

Thermogenesis is increased by the activity such as ________ or _________.

Answer 24

1. Moving

2. Shivering

Question 25

What is non-shivering thermogenesis?

Answer 25

Hormones (thermogen) causes the mitochondria to increase their metabolic activity.

Question 26

What does thermogen do to the body?

Answer 26

Produce heat, but uncoupled from the production of ATP.

Question 27

Do humans have brown fat?

Answer 27

Yes! It is thought that humans have it surrounding the neck and is active during cold stress.