Temperature and Thermoregulation

Question 1

Thermal strategies

Answer 1

Behavioural
Chemical
Physiological

Question 2

Behavioural strategies

Answer 2

migration

hibernation

Question 3

Chemical strategies

Answer 3

Cell membrane - phospholipids

Cholesterol: too hot is a liquid and too cold it hardens

Question 4

Physiological strategies

Answer 4

can build reserve from fat

Insulation

Question 5

what do physiological mechanisms need

Answer 5

to be charged

Question 6

what areas have more dramatic increases in temperature

Answer 6

big cities

Question 7

what is the ring of fire in Northern Canada

Answer 7

machines that melt permafrost

Question 8

Conduction

Answer 8

energy transfer from one object to another

Question 9

Convection

Answer 9

energy transfer between the animals and the moving mileu

Question 10

evaporation

Answer 10

thermal energy absorbed by the water on the surface of an object

Question 11

Radiation

Answer 11

emission of electromagnetic energy frmo an object

Question 12

thermal conduction

Answer 12

heat is conducted from internal tissues, throughout other tissues and fluids and into the surroundings

Question 13

High thermal conductivity

Answer 13

heat sink

water has higher thermal conductivity in air which is why it would loose heat faster

Question 14

what is heat lost too

Answer 14

moving fluid (water/air)

Question 15

Shiver

Answer 15

a muscle contraction to heat the boundary layer

Question 16

Bergmanns rule

Answer 16

states that animals living in cold environments tend to be larger than animals in warmer environments
(applies more to ectotherms)

Question 17

Allens rule

Answer 17

states that animals living in colder climates tend to have shorter extremities than animals in warmer climates

Question 18

what is insulation for animals

Answer 18

fur
feathers
blubber

Question 19

Fur and Feathers

Answer 19

• restricts movement between surface of animal and environment
• keratin
• traps air in between which keeps it warm
• thickness and density changes (better traps air)
• black bird controls piloerection at different temperatures
• thermal conductance through trapped air
• black absorbs wavelength but no reflects
• white reflects but absorbs heat
• polar bear (white absorbs and black causes less damage, hair is hollow)

Question 20

cons of fur and feathers

Answer 20

• uncommon to be main form of insulation for mammals
• compressible
• energy expensive

Question 21

blubber

Answer 21

• lipid layer distrupts the flow of thermal energy from the core to external surface of animal
• thicker layer = more insulation
• common insulation for marine mammals
• non compressible
• energy store

Question 22

poikilotherm

Answer 22

cannot regulate body temp and uses behaviour methods

Question 23

homeotherm

Answer 23

maintains body temp ( helps their nervous system)

Question 24

endothermic

Answer 24

animal generates internal heat to maintain a high body temperature

Question 25

ectothermic

Answer 25

environment determines the animals body temperature

Question 26

regional endothermy

Answer 26

heat will increase with MR allow certain parts of the body to be warm during vasoconstriction - aquatic animals have a system to regulate temperature in the body : rete mirabile they favour heat production with lots of mitochondria and vasoconstriction

Question 27

temporal heterotherms

Answer 27

-partial endotherms - when MR is reduced by the seasons or overnight - torpor - hibernating animals drop their temperature - while digesting prey the body temp will increase partial endotherm because they are internally generating heat

Question 28

regional heterotherm

Answer 28

- fish like marlin and sword fish can heat specific areas of their environment - Rete mirabile system used to maintain internal temperature - heat is generated through the digestive system and moved around by the body to the thermal exchange cells so that heat can be generated

Question 29

thermotolerance

Answer 29

animals have a characteristic degree of thermotolerance - ectotherms: changes in their TA alter body temperature directly changing rate of many biological processes - endotherms: respond to changes in TA by inducing regulatory responses

Question 30

thermal neutral zone

Answer 30

endotherm temperature tolerance range | - optimal temperature in which heat production is in equilibrium (heat loss and gain are the same)

Question 31

temperature effects on metabolism

Answer 31

- ectotherms: change in the TA affects body temperature and directly affects various biological processes - endotherms: a change in the TA induces a compensatory response - membrane must be given time to allow the membrane to be functionally at different temperature - phospholipids become more saturated during warmer temperatures while becoming less saturated in colder temperatures (homeoviscus adaptation)

Question 32

homeoviscus adaptation

Answer 32

- fatty acid chain length and saturated double bond - polar head phosphatidylcholine (PC) in heat - polar head phosphatidylethanol (PE) in cold - cholesterol: membranes are more liquid when external conditions change

Question 33

what are the two classes of macromolecules that are affected by temperature

Answer 33

proteins and lipids

Question 34

Ice crystals in tissues can have two harmful effects

Answer 34

- break membranes | - take water and causes a hyper osmotic stress

Question 35

ice nucleators

Answer 35

- affect calcium and salts will reduce temperature again | - help with freezing of membrane with changes from phospholipids

Question 36

ambient temperature

Answer 36

- how it varies is realized by thermoreceptors - thermoreceptors are in the abdominal regions, muscles and one more - controlled by sensors

Question 37

panting

Answer 37

found in many mammals important in species living in warm regions - gazelles, camels, canines, felines - absent in horses, rodents, primates and humans

Question 38

sleeping

Answer 38

- functioning of the brain - reduce body temperature - we go to sleep and sometimes wake up cold - use strategies in order to cool it down for sleeping

Question 39

torpor

Answer 39

- body temp is reduced - BMR is reduced - many different individuals - humming bird = small surface area and they lose heat at a higher rate temp drops to 13ºC

Question 40

estivation

Answer 40

- practiced by some mammals such as squirrels who spends the hottest part of summer sleeping in their burrows with body temp close to ambient temp

Question 41

hibernation

Answer 41

- physiological adaptation - survive when food availability is poor and cause a decrease in body temp and metabolism - accompanies by a significant decrease of internal temp to 1ºC only hibernating animals can survive this because for any other animal if it goes below 17ºC it is lethal - interrupted by periodic arousals of 'unpredictable' nature and temp increases to 37ºC - 75% time in orthodox sleep - awakeness is constant - pay attention to length of day, changes in temp and food availability to prepare for hibernation - bouts where they change from high to low - gets to a point where they need to get up to get energy.