In vertebrates nose have function to expel air for respiration in conjunction with mouth. As like human, behind nose are olfactory mucosa and sinuses. Behind the nasal cavity, air will passes through pharynx, shared with digestive system, then air into the rest of respiratory system.
As like in human vertebrates’ nose also have similar function like inhale air from the atmosphere and take oxygen after passes the lung then release carbon dioxide. In vertebrates nose also have inner hairs whose functions to stop unwanted particles from entering the lungs.
In wet nose like dogs is useful for the perception of direction. Sensitive to cold receptors in the skin detect the place where the nose is cooled the most and this is the direction a particular smell that the animal just picked up comes from. The sensitive of smell on Dog nose is better than other normal animals.
Different in reptiles, nose have function to sense of heat that can predict the distance of other animal. The nasal chamber is generally larger, with the choanae being located much further back in the roof of the mouth. In crocodilians, the chamber is exceptionally long, helping the animal to breathe while partially submerged. The reptilian nasal chamber is divided into three parts; anterior vestibule, main olfactory chamber and posterior nasopharynx.