Thermal relations

Question 1

Heat budget equation:

Answer 1

Hstored = Hmet + Hcd + Hcv + Hrd + Hev

Question 2

Hmet =

Answer 2

metabolism heat = always +

Question 3

Hcd =

Answer 3

conductance heat –> direct contact b/t surfaces –> +/-

Question 4

Hcv =

Answer 4

convection heat –> transfer b/t surface and fluid (gas or liquid) —> +/-

Question 5

Hrd =

Answer 5

radiation heat –> +/-

Question 6

Hev =

Answer 6

evaporation heat –> -

Question 7

Ectotherm

Answer 7

gain heat from environment

Question 8

Endotherm

Answer 8

capable of generating heat internally

Question 9

Homeotherm

Answer 9

maintains thermal homeostasis by generating heat through metabolism

Question 10

Poikilotherm

Answer 10

internal T varies significantly

Question 11

Heterotherm

Answer 11

a type of poikilothermy; homeothermic part of time, but may reduce metab rate, drop T, e.g., hibernators

Question 12

Physiological Mechanisms to maintain thermal balance (6)

Answer 12

*Evap HOH loss
*Heat windows (ears)
*Seasonal insulation Δ
*Shivering
*Non-shivering thermogenesisbrown fat
*Countercurrent heat exchangers

Question 13

Behavioral Mechanisms

Answer 13

• Burrowing
• Nocturnal behavior
• torpor = (hibernation / estivation)
  *shade seeking
  *hyperthermia
  *Heliothermism (basking)

Question 14

poikilotherms van’t Hoff’s rule

Answer 14

–for each 10oC ↑, O2 consumption2X
Q10 = RT / R(T-10)

Question 15

Basal Metabolic Rate (BMR)

Answer 15

the min E req to continue vital processes

Question 16

BMR in mammals and birds

Answer 16

Mammals VO2=0.676 Mb^0.75
Birds VO2=0.679 Mb^0.723

Question 17

Hibernation in small mammals

Answer 17

*Accumulate fat before entering
*Coord mvt. stops
*Pulse ↓, maybe intermittent
*↓ resp, metabolic rates 2-4% of normal
*0C < Body T <10C
*↑ blood CO2 Acidosis
*↓ glycolysis
*↓ shivering threshold
*↓ metabolic demand
*Kidney fn may cease

Question 18

Hibernation in bears

Answer 18

*not true heterotherms
*Quickly enter, easily roused
*Temp drops ~ 2-6oC
*Heart rate ↓ to <10 bpm
*Summer, fall eat ~20,000 kcal/day
*Winter: use ~4000 kcal/day

Question 19

Plant response to high Temp (3)

Answer 19

*Δ orientation to sun
*lose heat by transpiration,
reradiation, convection
*Thermotropism – mvt
toward or away from heat
*heat shockproteins, adapted to
higher T

Question 20

Plant responses to cold

Answer 20

*Frost hardening - ↑ sugars,
aa’s, non-toxics e.g. sugar
alcohols anti-freeze
*Thermotropism – mvt
toward or away from heat

Question 21

Ecotype

Answer 21

local pop’s adapted to specific env conditions