Respiratory Histology Flashcards
What are the two ‘divisions’ of the pulmonary tree?
conducting division and respiratory division
What are the structures associated with the conducting division of the pulmonary tree?
nasal cavities all the way down to terminal bronchioles (includes pharynx, larynx, trachea, 1 bronchi, 2 bronchi, 3 bronchi, bronchioles, and the terminal bronchioles
What are the structures associated with the respiratory division of the pulmonary tree?
respiratory bronchioles, alveolar ducts, alveoli
Where do you see a change from ring shaped to plate shaped cartilage on the pulmonary tree?
intrapulmonary bronchi
What are some distinguishing characteristics of intrapulmonary bronchi?
- cartilage changes from rings to plates
- there is lamina propria containing criss-crossing bundles of spirally arranged smooth muscle and elastic fibers
- lymphoid tissue becomes more abundant
The mucosa layer of the respiratory system contains what kinds of cells?
ciliated columnar cells, goblet cells, brush (chemosensory) and basal (stem cells for the epithelium) cells, lymphocytes
What layers of the pulmonary tree have epithelium?
ALL layers.
What layers of the pulmonary tree have goblet cells?
all the way down to segmental bronchi (i.e. no terminal bronchi or lower)
same abundance all the way until the main bronchi start, then tapers down
What layers of the pulmonary tree have ciliated cells?
all the way down to respiratory bronchioles (i.e. no alveolar ducts or further)
same abundance all the way until the terminal bronchi, then tapers down
What layers of the pulmonary tree have glands?
all the way down to segmental bronchi (i.e. no terminal bronchi or lower)
same abundance all the way until the lobar bronchi, then tapers down
What layers of the pulmonary tree have hyaline cartilage?
all the way down to segmental bronchi (i.e. no terminal bronchi or lower)
tapers down in abundance from the start of the trachea to where it ends
What layers of the pulmonary tree have smooth msucle?
all the way down to alveolar ducts (i.e. no alveolar sacs or further)
same abundance all the way until the terminal bronchi, then tapers down
What layers of the pulmonary tree have elastic fibers?
ALL layers
same abundance all the way until the alveolar ducts, then tapers down
How does/can smoking affect the trachea and bronchi in terms of epithelial?
1) smoking can introduce chronic irritants to the PSCC epithelium in these structures.
2) chronic irritants can cause the epithelial cells to lose their coordinated patterns, which can impact mucous removal, and eventually chronic coughing as a result
3) chronic coughing causes PSCC epithelium to undergo columnar-to-startfied squamous metaplasia (reversible but damaging particularly in trachea)
NOTE: squamous cell carcinomas have their origin in metaplastic epithelium
What kinds of characteristics of bronchioles distinguish them?
only the mucosa layers remain (no muscularis externa or adventitia) submucosa layer and its glands are gone
few or no goblet cells
has Clara cells
epithelial cells are more cuboidal than columnar (PSCC cells still present)- more so toward terminal bronchioles
muscularis mucosa is well developed