Respiratory bronchiole                           Chart

                          
Cell types: Ciliated, brush, 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. Respiratory bronchiole has simple cuboidal epithelium as the alveolar ducts but lumen leads to alveolar ducts.

Roll over mouse

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 but simple cuboidal type and there is NO cartilage in adventitia. Lumen leads to alveolar ducts.
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.

 

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 cuboidal epithelium with then picks both alveolar ducts and respiratory bronchiole but alveolar ducts do not have any thick specialized wall except for basement membrane and few scattered myocytes.

Note the mucosa and its epithelial cell varieties.

 

Level 1: Select  compact
Level 2: Select connective tissue from list of sclerous, muscular, connective, organ-glands and nervous tissues since there is heterogenous collection of cells and fibres.
Level 3: Select spaces with the visibility of some thinness and spaces of tissue compactness. This will select both areolar and adipose tissues.
Level 4: Select nofibres and this will eliminate areolar tissue which has many fibres criss-crossing and parallel running..

Do you think this is a section of subcutaneous tissue or internal part of organ, or omentum or mesentery?

 

http://www.oluwoleogunranti.com  ŠThe Human Anatomy Museum