4 concepts
The Respiratory System and Direct Diffusion
Respiratory processes that help organisms exchange O2 and CO2 range from simple direct diffusion to complex respiratory systems.
Skin, Gills, and Tracheal Systems
Respiration can occur using a variety of respiratory organs in different animals, including skin, gills, and tracheal systems.
Amphibian and Bird Respiratory Systems
Birds and amphibians have different oxygen requirements than mammals, and as a result, different respiratory systems.
Mammalian Systems and Protective Mechanisms
The mammalian respiratory system equilibrates air to the body, protects against foreign materials, and allows for gas exchange.