Gas exchange in Amphibians, Reptiles and Birds

Amphibians gas exchange through _______ and _______.

Frogs draw air into mouth by ______________ muscles in their _______ and mouth.

During hibernation, gas exchange occurs exclusively throuh _______

skin and lungs

contracting

throat

skin

Reptiles have _______ lungs which leads to more gas exchange than amphibian lungs due to the _______ internal structure.

Reptiles cannot exchange gases through_______.

Most reptiles have _______ lungs

Some snakes have _______ lungs

spongy

complex

skin

two

one

Birds have lungs and _______ _______.

> Air sacs are _______ sites of gas exchange

> Air sacs enable a _______ way flow of air through lungs.

Birds do not have a ______________ but their ribs and flight muscles ______________ their lungs more efficiently

air sacs

not

one

diaphragm

ventilate

Lung adaptations for Amphibians

Skin also for exchange

O2 via positive pressure into air sacs

Lung adaptations for birds

One way flow increases efficiency

2 cycles to compare

Lung adaptations for mammals

Negative pressure

Incomplete removal

Myoglobin content varies