EM 077 Respiratory Epithelium

Respiratory Epithelium

Scanning electron microscopy (SEM) of a cross-section of the epithelium that lines the lumen of thw trachea.

Although this is a pseudostratified columnar epithelium, the shape of the cells and the number of layers can not be determined from this micrograph. Only the apical surface (tan) of the epithelium can be seen.

Some of the cells have both cilia and microvilli on their apical surface. They can be distinguished from each other because cilia are much longer than microvilli.

• Cilia (orange) - ~8 to 10 µm in length and 250 nm in diameter
• Microvilli (yellow) - ~1 µm in length and 100 nm in diameter
• Epithelia cells - damaged by cutting of the specimen

The pseudostratified columnar cells with cilia and goblet cells found in airways is also known as respiratory epithelium.