1. The Respiratory System
Trachea (No.3)
Lung (No.31)
Jun Zhou
School of Medicine, Zhejiang University

2. Trachea
C-shape hyaline cartilage
Mucosa
Submucosa
adventitia

3. Mucosa:ciliated,pseudostratified epithelium+lamina propria
Submucosa:denser CT+mucous,serous glands
Adventitia:hyaline cartilage+CT

4. Posterior border: numerous glands+ smooth muscle

5. Pseudostratified columnar ciliated epithelia
goblet cell, cilia cell and basal cell, brush cell and small granule cell
Obvious basement membrane
Tracheal glands
(serous, mucous)

6. Lung Conducting portion: Small bronchi Bonchioles Terminal bronchioles
Respiratory portion:
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli

7. Human lung (NO.31) Respiratory bronchiole Bronchiole
Terminal bronchiole
Bronchia

8. Conducting portion
Bronchiole
Bronchia
Terminal bronchiole

9. Small bronchi
pseudostratified ciliated epi.
Smooth muscle in lamina propria
Incomplete cartilage rings

10. Bronchiloes
Smaller lumen and thinner wall
Epi from pseudostratified columnar to simple cuboidal
Rare goblet cell, glands and cartilage
More smooth muscle

11. Terminal bronchiloes
Simple cuboidal ciliated epi.
No glands, cartilage
Completed layer of smooth layer

12. Respiratory branchioles:
Wall with alveoli opening on it.
Alveolar ducts:
Almost no walls, with smooth muscle knob
Alveolar sacs:
No smooth muscle knob
Alveoli:
Actual site of gas exchange

13. respiratory portion
Alveolar duct
Respiratory bronchiole
Alveolar sac

14. Pulmonary Alveoli Type I alveolar cell Type II alveolar cell
Alveolar septum

16. Dust cell
phagocytose carbon or dust particles

17. Alveoli with dust cells in the septa

19. Blood-air barrier

21. The end!