MHS 222 Trachea

Trachea

This semi-thin section (~1.0 µm thick) of the trachea has excellent cellular definition compared to normal sections (4 to 6 µm thick).

• Respiratory Epithelium - the trachea is lined with a pseudostratified columnar epithelium with cilia and goblet cells.
  • Columnar Cells - nuclei occur at different levels.
    • Cilia - extend 5 to 7 µm from the surface of the columnar epithelial cells. The dark line at their base is from their basal bodies.
  • Basal Cells - small cells found at the base of the epithelium that do not extend to the surface.
  • Goblet Cells - scattered cells that secrete mucus. They are difficult to identify in this specimen.
  • Basement Membrane - separates the epithelium from the underlying connective tissue. It is seen as a thick, eosinophilic band beneath the epithelium
• Lamina Propria - dense irregular connective tissue supports the epithelium.
  • Sero-Mucous Glands - add moisture to air and aid in trapping contaminants.
• Tracheal Cartilage - partial cross-section of a hyaline cartilage ring.
  • Perichondrium - a layer of dense irregular connective tissue that surrounds the cartilage.