BIOE129 Week 4 Thermoregulation

Convection

heat transfer due to movement of a fluid

Conduction

heat transfer due to physical contact of solids

What is the heat loss equation

kA(Th-Tc)/L

Explain the heat loss equation

k = conductivity of insulation material

A = body surface area

Th - Tc = temperature difference between body and water

L = thickness of insulation

What is the thermal neutral zone

Its a range of environmental temperatures where the body core temperature is maintained without increasing metabolism

What is Countercurrent Heat Exchange

highly efficient process where two fluids (like blood, air, or water) move in opposite directions right next to each other, allowing heat to transfer from the hot fluid to the cold fluid

The first advanatge of fur

lighter

The first advantage of blubber

can withstand fouling

The second advantage of fur

better insulation for given amount

The second advantage of blubber

does not compress with depth

The third advantage of fur

skin is maintained at or near body temperature

The third advantage of blubber

perfuse to bypass and dump heat also energy storage capabilities

The first disadvanatge of fur

needs to kept clean/groomed

The first disadvantage of blubber

constrains size and maneuverability

The second disadvantage of fur

compressible so insulation declines with depth

The second disadvantage of blubber

difficult to grow or divide live tissue at low temps

The third disadvantage of fur

increases drag/reduces hydrodynamics

The third disadvanatge of blubber

must haul out or move to warmer environments to molt and heal wounds

Radiation

transfer of radiant energy

Evaporation

heat absorbed from phase change liquid to water vapor (sweating, respiratory water loss)