To function efficiently, all specialized respiratory organs across species share several key physical characteristics:
: A dense network of capillaries surrounds the respiratory surface to transport absorbed oxygen throughout the body immediately. Diversity of Respiratory Systems respiratory organ
: Millions of tiny structures (like alveoli in humans or filaments in fish) maximize the area available for gas to cross into the blood. While humans rely on lungs, the animal kingdom
). While humans rely on lungs, the animal kingdom features a wide variety of respiratory systems adapted to diverse environments, from the deep ocean to high altitudes. Primary Features of Respiratory Organs : Gases must dissolve in liquid before they
: Respiratory surfaces consist of incredibly thin, squamous epithelial cells. This "air-blood barrier" must be as thin as possible to allow for rapid diffusion.
: Gases must dissolve in liquid before they can diffuse across a membrane, meaning respiratory organs must remain moist to function.