Anatomy
In humans and other mammals, the anatomy of a typical respiratory system is the respiratory tract. The tract is divided into an upper 詳細

Cetaceans
Horses
Horses are obligate nasal breathers which means that they are different from many other mammals because … 詳細

The anatomical structure of the lungs is less complex in reptiles than in mammals, with reptiles lacking the very extensive airway tree structure found in mammalian lungs. Gas exchange in reptiles still occurs in alveoli however. Reptiles do not possess a 詳細

Oxygen is poorly soluble in water. Fully aerated fresh water therefore contains only 8–10 ml O2/liter compared to the O2 concentration of 210 ml/liter in the air at sea level. Furthermore, the 詳細

The respiratory system of birds differs significantly from that found in mammals. Firstly, they have rigid lungs which do not expand and contract during the breathing cycle. Instead an extensive system of air sacs (Fig. 15) distributed throughout their bodies act as the bellows … 詳細

Both the lungs and the skin serve as respiratory organs in amphibians. The ventilation of the lungs in amphibians relies on positive pressure ventilation. Muscles lower the floor of … 詳細

Arthropods
Some species of crab use a respiratory organ called a branchiostegal lung. Its gill-like structure increases the surface area for gas exchange which is … 詳細