Thermoregulation: Thermoregulation: temperature balancetemperature balance

Hannah NevinsBio 1b: ZoologySpring 2009

Thermal Strategies:Thermal Strategies:

Ectotherms◦ Heat generated

from outside◦ Rely on external

sources (e.g. solar radiation)

◦ e.g. reptiles

Endotherms◦ Heat generated

from “within”◦ Rely on metabolic

heat production◦ e.g. Mammals,

birds

Adaptations:• Anatomical

• insulation - fur, feathers, blubber• heat radiators – big ears

• Physiological• circulation• counter-current

• Behavioral• huddling• bathing

Whale Blubber: fat & Whale Blubber: fat & connective tissueconnective tissue

Behavioral mechanisms to loss heat: panting, seeking shade

Counter-current Heat Counter-current Heat Exchange:Exchange:

Integument: role in Integument: role in thermoregulationthermoregulation

Frostbite: tissue damage Frostbite: tissue damage from coldfrom cold

HypothalamHypothalamus: us: thermostatthermostat

Antarctic Ice FishAntarctic Ice Fish

• Antifreeze blood – glycoproteins• Lack RBCs and hemoglobin (vestigial DNA coding for Hb, Mb)