A scanning electron microscopic study of the equine upper respiratory tract.

The research presents an electron microscopic study of the surface features of the upper respiratory tract in normal horses. It identified a non-ciliated epithelial area in the rostral portion of the nasal cavity and a ciliated area extending into the nasopharynx and guttural pouches with some non-ciliated cells.

Objective of the Study

• The main goal of the research was to examine the surface features of the upper respiratory tract of 20 healthy horses of varying ages and types using scanning electron microscopy.

Methodology of the Research

• The researchers made use of scanning electron microscopy, a powerful microscopy technique, to obtain a detailed visual study of the equine upper respiratory tract.
• The studied horses were of various ages and types and were clinically normal, which provides an understanding of the standard conditions of the upper respiratory tract in horses.

Findings of the Study

• In the rostral part, which is the front end of the nasal cavity, the researchers found a large area of non-ciliated epithelium. Non-ciliated epithelium are cells without hair-like projections (cilia) on their surfaces.
• Conversely, the caudal part of the equine’s nasal cavity, which is towards the rear end, was well ciliated, having many cells with cilia on their surface. The ciliated type of epithelial cells extended to the nasopharynx (back part of the throat) and the guttural pouches (air-filled extensions from the Eustachian tube in horses).
• However, the researchers also discovered scattered areas of non-ciliated microvillous cells in the nasopharynx and guttural pouches. These are epithelial cells, but instead of cilia, they have minute hairlike structures called microvilli on their surfaces.