ventral nasal meatus
The ventral nasal meatus is found between the ventral nasal concha and the dorsal surface of the hard palate.It connects the nasal vestibule with the nasopharynx. Rostrally it is narrow at the nasal vestibule and widens caudally towards the nasopharyngeal meatus. The ventral nasal meatus is the main passage for air. Apart from olfaction, the nasal cavity functions to warm the inhaled air as it passes through the meatuses over the vascular beds of the mucosa. The air is humidified by the vaporization of tears and serous nasal secretion. The air is cleaned throughout the scattered mucous glands. These glands secrete mucous through the nasal cavity and the mucous serves to trap the large particles that come into contact with it. Clinically in the horse the ventral nasal meatus is the main passage through which a stomach tube can be passed to the pharynx and oesophagus and then to the stomach. This kind of a tube is commonly used when drenching a horse for colic, as well as having many other veterinary applications. The tube has to pass through the ventral nasal meatus to the nasopharyngeal meatus and the caudal nares to reach the pharynx and oesophagus. If the tube is accidentally passed into the dorsal or middle nasal meatuses it would pass to the ethmotubinates and cause massive haemorrhage.