PSEUDOSTRATIFIED EPITHELIUM – 2
The pseudostratified epithelium shown in the figure lines inner cavity of the trachea. It is also called respiratory epithelium although it does not participate in the exchange of gases between the blood and the inhaled air.
Observe the nuclei at various heights of the epithelial layer, but they are not distributed in distinct layers, as would be the case of the stratified cubic-prismatic epithelium seen previously.
Place the cursor or click on the figure to see epithelial cell nuclei – some nuclei of columnar cells are highlighted in light blue and of some basal cells in dark blue. Below the nuclei of basal cells you find connective tissue.
Between the epithelial cells you can see secretory epithelial cells called goblet cells, which secrete mucus. Their cytoplasm is poorly stained, because mucus does not stain well with hematoxylin and eosin staining. Their nuclei, well stained by hematoxylin are placed at the base of the cell.
A goblet cell nucleus is seen highlighted in dark green after moving the mouse. Its cytoplasm, where the secretion is concentrated, appears in light green.
Observe the nuclei at various heights of the epithelial layer, but they are not distributed in distinct layers, as would be the case of the stratified cubic-prismatic epithelium seen previously.
Place the cursor or click on the figure to see epithelial cell nuclei – some nuclei of columnar cells are highlighted in light blue and of some basal cells in dark blue. Below the nuclei of basal cells you find connective tissue.
Between the epithelial cells you can see secretory epithelial cells called goblet cells, which secrete mucus. Their cytoplasm is poorly stained, because mucus does not stain well with hematoxylin and eosin staining. Their nuclei, well stained by hematoxylin are placed at the base of the cell.
A goblet cell nucleus is seen highlighted in dark green after moving the mouse. Its cytoplasm, where the secretion is concentrated, appears in light green.
Another important feature of the epithelium lining the trachea is the presence of cilia on the free surface of its columnar cells. They represent the pink band after moving the mouse or clicking
