Homeostasis
the 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.
Reduce Activity
Levels (Rest)
Find a cool spot
Cool it!
Pant
Sweat
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.