Homeostasisthe physical process that maintains a

stable internal environment.

(example: body temperature)

Endotherms• animals that can generate

& regulate their own body heat.

• Their body temperature stays at a relatively constant level by balancing heat loss with heat production.

• sometimes referred to as "warm-blooded"

Minimize Heat Loss

• Heat loss is minimized in most mammals by having a thick coat of fur or thick layer of fat beneath the skin.

Making Some Heat

• Digestion- Endotherms have to eat fairly often because they burn calories to support their body temperature as well as other functions.

• Shivering – An involuntary movement that generates heat.

Cool it!Find a cool spot

PantSweat

Reduce Activity Levels (Rest)

All Ears!Radiator ears are a special

adaptation

Some animals have large ears that have blood vessels close to the surface of the skin. If the outside temperature is cooler, heat is released through the ears.

Ectotherms• animals that rely on

environmental sources of heat.

• sometimes called “cold blooded” animals, are poorly insulated and produce heat at a low rate compared with endotherms. They also lose heat to cooler surroundings quickly.

• regulate their body temperatures by behaviors.

Regulate Body Temperature

• Many ectotherms are able to regulate their body temperature behaviorally, by moving into and out of sunlight.

• burrowing under ground /seeking shade

• Moving in and out of water.

They Just Don’t Need the Calories!

• They therefore eat only 1/3 to 1/10 of the food needed by endothermic animals.

• an ectotherm has all this energy available for activity, growth, repair and reproduction.

http://www.statemaster.com/encyclopedia/Ectothermic

Don’t eat very often.

Types of Ectotherms

• Reptiles

• Amphibians

• Fish

• Insects

How?

• Snakes and lizards sunning themselves on rocks.

• Fish changing depths in the water to find a suitable temperature.

• Desert animals burrowing beneath the sand during the day.

• Insects that warm their flight muscles by vibrating them in place.