Middle nasal meatus

The middle nasal meatus (Meatus nasi medius) is located between the two conchae. In most species, it widens at its caudal part and someway forks to admit the great volute of the ethmoid bone, that forms the middle concha (Concha nasalis media). It is not much developed in Equidae and Pigs.

The sinuso-nasal communications usually open in the caudal part of the middle meatus. On the lateral wall of this meatus opens the lacrymal duct (Canalis lacrimalis) on the caudal part, which is continued forward by the nasolacrymal groove (Sulcus nasolacrimalis), which corresponds on the living to the nasolacrimal duct (Ductus nasolacrimalis).