thermoregulation 1

Question 1

external heat source

Answer 1

the sun, burning organic material

Question 2

internal heat source

Answer 2

cellular metabolism

Question 3

cellular metabolism

Answer 3

energy extracted from food and converted partially into heat

Question 4

anabolic

Answer 4

building complex structures from small monomers

Question 5

catabolic

Answer 5

breaking down complex structures into small monomers

Question 6

mass specific metabolic rate

Answer 6

sum catabolic + anabolic

Question 7

oxyregulators

Answer 7

Mr maintained at a lower level during hypoxia
hypoxia tolerant
can survive low o2 - produces lactic acid

Question 8

oxyconformers

Answer 8

Mr decreases rapidly during hypoxia
hypoxia intolerant

Question 9

core body temperature (Tc)

Answer 9

internal Tc roughly in the center of the body
can be dependent or independent of environment
optimized for physiology

Question 10

TRP channels

Answer 10

open and close as a function in C
detect internal T

Question 11

poikilotherm

Answer 11

Tc varies considerably with environmental changes
reptiles, fish, insects

Question 12

homeotherms

Answer 12

Tc does not vary with environmental changes
mammals, birds

Question 13

heterotherms

Answer 13

Tc has characteristics between the two

Question 14

endotherm

Answer 14

capable of self generation to maintain Tc
midway between freezing and boiling
more complex
more mitochondria

Question 15

endotherm

Answer 15

capable of self generation to maintain Tc
midway between freezing and boiling
more complex
more mitochondria

Question 16

ectotherm

Answer 16

requires external heat sources to maintain Tc
small or negligible internal heat production
rely on environmental heat sources
greater tolerance of T extremes
need less food to survive

Question 17

mesotherm

Answer 17

can use metabolic rate to raise Tc above ambient

Question 18

gigantotherm

Answer 18

low metabolic rate able to elevate Tc as a result of high body mass and increased capacity to maintain heat
change in conduction and convection

Question 19

basoendotherm

Answer 19

Tc <35C
lowest body temp of any mammal
primarily nocturnal

Question 20

factors that affect Tc

Answer 20

metabolic activity - o2 consumption
environment
size
tissue placement

Question 21

counter-current heat exchanger

Answer 21

blood vessels placed next to each other
warm blood moves in one direction, cool blood in the other

Question 22

specific heat capacity

Answer 22

the amount of heat required to raise the T of 1kg of any substance 1C
how easy it is to gain and lose heat

Question 23

K

Answer 23

ability to transfer heat
higher K indicates rapid heat transfer
materials with low K are effective insulators

Question 24

what causes a change in K

Answer 24

reducing blood flow to the skin surface
posture (fetal position)
changing skin
hair and feather coloration

Question 25

decreases K

Answer 25

feather lubrication with oil
fluffing feathers
posture (minimizing s/v ratio)
changing skin color (lizards)
seasonal hair

Question 26

heat balance eqaution

Answer 26

HE + HC + HR (losses) = HT + HC + HS (gains)

maintaining internal Tc at an optimal T by balancing heat gain and heat loss

Question 27

HE

Answer 27

evaporation of water
sweat glands, panting

Question 28

HT

Answer 28

thermogenesis - brown adipose tissue
heat produced as product of metabolism
through muscular activity (shivering)

Question 29

thermogenesis

Answer 29

increased metabolic activity
reduced metabolic efficiency - uncoupling proteins (UCP)
all energy is lost as heat
[no coupling of ATPase –> energy has to be lost somewhere –> heat]

Question 30

brown adipose tissue

Answer 30

high number of mitochondria, iron - brown
high number of capillaries, high oxygen demand
UP1 expression

Question 31

HC

Answer 31

heat flow from animal to environment
insulation - fur, feathers, subcutaneous fat, trapped air

Question 32

possible causes of death from lethal T (TL)

Answer 32

protein denaturation
enzyme inactivation - Q10
inadequate o2 supply - lack of o2 to support Mr
cascade failure - disruption of biosynthetic pathways
membrane fluidity - changes in the cell membrane