Homeostasis

Question 1

What best describes the limits to life on earth?

Answer 1

the freezing point of water and the temperature when proteins denature (0 - 40 degrees Celsius)

Question 2

If the Q10 of animal’s metabolic rate is 2, then –

Answer 2

the animal consumes 1/2 as much oxygen per hour at 20 degrees then 30 degrees Celsius

Question 3

What statement about brown fat is true?

Answer 3

it produces heat without producing much ATP

Question 4

What’s the most important and most general characteristic of endotherms adapted to cold climates compared with endotherms adapted to warm climate?

Answer 4

greater insulation

Question 5

what would cause a decrease in the hypothalamic temperature set point for metabolic heat production?

Answer 5

taking an aspirin when you have a fever

Question 6

Because of their – endotherms expend more energy (thus more heat) just to maintain the ion concentration gradients across their membranes

Answer 6

leaky membranes

Question 7

sum of total energy expenditures in body at rest

Answer 7

metabolic rates

Question 8

True or False: behavioral thermoregulation is exclusive to ectotherms

Answer 8

False

Question 9

energy budget

Answer 9

heat in = heat out

metabolism + R in = R out + convection + conduction + evaporation

Question 10

surface temperature can be controlled by altering the – to the skin

Answer 10

flow of blood

Question 11

mammals have specialized blood vessels for transporting heat to –

Answer 11

hairless surfaces of the skin

Question 12

cold fish: heat that blood picks up from metabolically active muscles is – to water flowing across its gills

Answer 12

lost

Question 13

hot fish: heat rows from warm blood to cold blood by –

Answer 13

conduction

Question 14

the internal body temperature of a hot fish is – than water temperature

Answer 14

greater

Question 15

for hot fish, 10 degree Celsius increase in muscle temperature, increases fish sustainable power –>

Answer 15

faster

Question 16

True or False: Some ectotherms regulate metabolic heat production

Answer 16

true (insects - scarab beetle, worker bees)

Question 17

How to determine metabolic rate by measuring what?

Answer 17

oxygen consumption or carbon dioxide production

Question 18

within a narrow range of environmental temperature, the metabolic rates of endotherms are at low levels and independent of temperature

Answer 18

thermoneutral zone

Question 19

resting animal is consuming enough energy to carry out its minimal body functions

Answer 19

BMR

Question 20

BMR of elephant is – than the BMR of mouse

Answer 20

greater

Question 21

BMR per gram of tissue increases as an animal gets –

Answer 21

smaller

Question 22

Endotherms respond to cold by producing – and adapt to cold by reducing –

Answer 22

heat, heat loss

Question 23

birds only use – heat production

Answer 23

shivering

Question 24

non shivering heat production occurs in –

Answer 24

brown fat cells

Question 25

thermogenin is found in

Answer 25

brown fat cells

Question 26

brown fats are – in some adults

Answer 26

small

Question 27

– can be found in animals acclimatized to cold or hibernation

Answer 27

brown fat cells

Question 28

most common and important means of decreasing heat loss

Answer 28

increasing thermal insulation

Question 29

other ways to decrease heat loss include

Answer 29

decrease blood flow to skin (constriction of blood vessels in skin) and countercurrent heat exchange

Question 30

for exercising animals, overheating can occur even at

Answer 30

low environmental temperatures

Question 31

sweating and panting are – process that require expending metabolic energy (generate heat in the process of dissipating heat)

Answer 31

active

Question 32

slight cooling of hypothalamus

Answer 32

constriction of skin blood vessels

Question 33

stronger cooling of hypothalamus

Answer 33

increases metabolic heat production

Question 34

heated hypothalamus

Answer 34

metabolic rate and body temperature falls and favors heat loss

Question 35

hypothalamus itself is a major – that generates set points for thermoregulation responses

Answer 35

feedback signal

Question 36

change in skin temperature is a – that shifts hypothalamic set point

Answer 36

feedforward information

Question 37

hypothalamic set point – when awake or active

Answer 37

increases

Question 38

set point for metabolic heat production is – when skin is cold

Answer 38

higher

Question 39

a rise in body temperature in response to pyrogens

Answer 39

fever

Question 40

pyrogens like foreign proteins produced by bacteria or virus

Answer 40

exogenous

Question 41

pyrogens like substances produced by immune cells in response to infection

Answer 41

endogenous

Question 42

during a fever, the body temperature rises until you match –

Answer 42

new set point

Question 43

aspirin – set point to normal so you feel –

Answer 43

lowers, hot

Question 44

some animals conserve energy by turning –

Answer 44

down thermostat

Question 45

below normal body temperature

Answer 45

hypothermia

Question 46

some animals undergo – to survive periods of cold and food scarcity

Answer 46

regulated hypothermia

Question 47

regulated hypothermia can last for

Answer 47

days or even weeks

Question 48

some small endotherms with high metabolic rates such as hummingbirds can survive without food (normally inactive)

Answer 48

daily torpor

Question 49

body temperature falls close to ambient temperature (1/15 of BMR)

Answer 49

hibernation