Terminal bronchiole

Terminal bronchiole Chart

Cell types: Ciliated, brush, basal, goblet, Clara, argentaffin-endocrine cells

Differential diagnosis:
All small hollow organs (non-respiratory and respiratory) are distinguished on the basis of availability of distinct outer coat. Appendix or oviduct do have distinct coats and should therefore not be confused with respiratory small luminal organs. Bronchus can be distinguished from bronchioles by the presence of submucous glands, goblet cells and also pseudostratified epithelium in the bronchus. Terminal bronchiole has simple columnar epithelium and no pseudostratified epithelium. In this feature it is similar to appendix or oviduct.

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Diagnostic Features:
a. Tissue is hollow and presents with a small lumen which fills less than 1/10th of low power field.
b. The epithelium is NOT of pseudostratified variety and there is NO cartilage in adventitia.
c. There is some muscular tissue in adventitia but no submucous glands, no goblets cells and no distinct outer coat. Lung tissue alveoli are present in abundance.

Draw your own section here and make your diagnosis by data base selection below

Database selection:

Practical

Tissue

Gross

Level 1: Select hollow since the small bronchus is a hollow organ
Level 2: Select small as opposed to large since lumen fills less than 1/10th of low power field for tissues of rat to man. This will select from database both cartilage and non cartilage containing tubes.
Level 3: Select no distinct outer coat since the coat merges with surrounding lung tissue.
Level 4: Select no cartilage which is not found in adventitia. This eliminates bronchus.
Finally select no goblet cell which distinguishes the terminal bronchiole from bronchiole

Note the mucosa and its epithelial cell varieties.