Distribution of epithelia in the nasal cavity of piglets.

The epithelial distribution in the nasal cavity of piglets was studied by serial transverse sections. The epithelial distribution in the nasal cavity of healthy piglets varied according to the age of the animal. The transitional epithelium, which contained goblet cells but no ciliated cells, occupied a smaller proportion of the nasal cavity in the newborn piglets than in the 4-week-old piglets. The ciliated epithelium extended more rostrally in the newborn piglets and covered the non-mineralized rostral portion of the nasal ventral concha. At 28 days of age, the rostral cartilaginous concha is overlaid by the transitional epithelium, the respiratory epithelium covering the mineralized nasal ventral concha. The variations in the epithelial distribution according to age are discussed with regard to the greater susceptibility of newborn piglets to bacterial infection.