13. Histology of the respiratory system

Question 1

Histology of the trachea

What is this?
What can be found in it?

Answer 1

Trachea, C shaped cartilage ring with tracheal muscle T connecting the ends
Tall pseudo stratified columnar cells, basal cells, goblet cells

Question 2

Histology of the trachea

Answer 2

Question 3

Trachea histology

Answer 3

Question 4

What is the difference between extrapulmonary and intrapulmonary bronchi?

Answer 4

• Extrapulmonary (or primary bronchus near the trachea): Similar to trachea but less goblet cells, Lamina propria has more elastin, Submucosa has less seromucinous glands, cartilage is interconnected plates
• Intrapulmonary (or tertiary bronchus): Lamina propria is encircled by smooth muscle, not many seromucous glands, cartilage is reduced to a few irregular plates

Question 5

What are goblet cells, basal cells and cillia cells and where are they found?

Answer 5

Goblet cells: produce mucus
Basal cells: provide attachment for cillia/goblet cells to basal laminae

All found in pseudostratified columnar epithelium of respiratory epithelium

Question 6

What are some histological features of bronchioles?

Answer 6

no cartilage/glands
Ciliated columnar epithelium with some goblet cells but these are replaced by Clara (replace damaged cells) cells in terminal bronchioles.
Smooth muscle is still there (M)

Question 7

What is the level of histology layers in the trachea?

Answer 7

Respiratory epithelium, BM, lamina propria, submucosa, Fibroelastic tissue, cartilage