1. Respiratory
system

2. Respiratory system

3. Nasal cavity, pharynx & larynx.
Trachea & bronchi.
Lung.

4. 一、trachea

5. mucosa
submucosa
adventitia
trachea (HE)
Mixed gland

6. EM: epithelium of trachea
1.Ciliated C
2.Brush C
3.Goblet C
5.Basal C
4. Small granule C

7. The wall of trachea 1. Mucosa=epithelium+lamina propria
pseudostratiated ciliated columnar…
Ciliated C, goblet C, brush C,
basal C, small granular C.
2. Submucosa=CT+ mixed glands
3. Adventitia=16-20 ‘C’ shaped hayline cartilage rings.

8. 二、lung bronchiole Gas exchange lung atmosphere & alveoli alveoli &
blood
(blood & tissue)

9. Lung
Low power

10. lung parenchyma: bronchial trees & alveoli .
Principal bronchi(Br)—lobular、segmental Br—smaller Br—bronchiole—terminal bronchiole—respiratory bronchiole—alveolar duct、alveolar sac—alveoli.
Conduction portion : above terminal bronchioles.
Respiratory portion :respiratory bronchiole to alveoli.
Pulmonary lobule: bronchiole and it’s ramifications.

11. Epithelium Goblet C Glands Cartilage plate SMC Conduction portion－
lobular Br & small Br
Epithelium
Goblet C
Glands
Cartilage plate
SMC

12. Simple ciliated columnar. Goblet C （－） Gland （－） Cartilage plate （－）
Conduction portion－
bronchiole &
terminal brochiole
Simple ciliated columnar.
Goblet C （－）
Gland （－）
Cartilage plate （－）
SMC

13. Rules of structural variance in conducting portion
Small Br
bronchiole
Terminal bronchiole
Epi
Pseudostratified
Ciliated columnar
Simple ciliated
columnar
Simple columnar** clara
cell
Goblet C
+ +
+/- -
Mixed gland
Cartilage plate
SMC +
+ ++

14. Respiratory bronchiole
Respiratory portion－
Respiratory bronchiole
The wall is interrupted
Simple cuboidal Epi, clara C
SMC

15. Alveolar duct & alveolar sac
Respiratory portion－
Alveolar duct & alveolar sac
Alveolar duct
The wall, many alveoli
SMC**
Simple cuboidal, squamous
Alveolar sac
No SMC**

16. Respiratory portion－alveolus
肺泡管
Simple alveolar Epi.

17. (1) Respiratory portion
###constituents：respiratory bronchiole，alveolar duct，alveolar sac，alveolus。
1.Respiratory bronchiole
The wall, few alveoli open into.
Simple cuboidal Epi,SMC.

18. (2) Respiratory portion
2.Alveolar duct & alveolar sac
The wall, many alveoli open into.
Knobs in the wall of alveolar duct
Knobs is sphincter-like SMC.

19. (3) Respiratory portion
3. alveolus:
type I alveolar C
type II alveolar C
alveolar septum.

20. macrophage
Type II alveolar C
Elastic fiber

21. type I alveolar C

22. Type II alveolar C
Osmiophilic Multilamellar bodies

23. blood-air barrier

24. Alveoli Type II cell Type I cell
squamous, covered most surface of the alveoli .
Type II cell
LM: round or cuboidal, cell body protrude into the lumen.
EM: osmiophilic multilamellar body, with abundant phospholipids.
Functions: secret surfactant, reduce surface tension, stabilize alveoli.

25. Alveolar septum: continuous Cap., elastic fiber. macrophage dust C.
@blood-air barrier includes:
1.mucus layer on surface of alveoli
2.type I alveolar C
3.BM of alveolar C
4.delicate layer of CT
5.continuous Cap. BM
6.continuous Cap. Endothelium.

26. Terminal bronchiole Respiratory bronchiole Alveolar duct Alveolar sac1
Terminal
bronchiole
Respiratory
bronchiole 2
Alveolar duct 3 4
Alveolar sac

27. Rules of structural variance in respiratory portion
wall
Epi.
SMC
Respiratory bronchiole
Not integrated
Alveoli open
Simple columan
Simple cuboidal
thin
Alveolar duct
Many alveoli open into
A few
Alveolar sac
of alveoli
Alveolar Epi. no
alveolus
Irregular vesicular

28. Alveolar epithelial cell
shape
cytoplasm
functions
Type I
squamous
Phagocytotic vesicle
Covered 95% of the surface of alveoli to benefit gas exchange.
Type II
round
cuboidal
Osmiophilic multilamellar body
Secret surfactant to reduce surface tension and stabilize the alveoli. **
Type I cell can not regenerate.
Type II cell can differentiate into Type I cell .

29. keypoints The basic structure of trachea.
Histologic structure of conduction portion.
Histologic structure of respiratory portion.
Esp. the alveolar epithelium

30. Thank you !