histology of respiratory system upper and lower rHistology is a vast and complex field, but it provides valuable insights into the structure and function of tissues in various organisms. It has played a major role in advancing our understanding of health, disease, and biology.

1. about Author
Mohamed Taha AL ashram
Veterinarian
Author
instructor
Histology of respiratory system for medical
students
1

2. Copy write
Histology of respiratory system for medical
students
2
All rights reserved.
No part of this publication
may be reproduced,
stored in a retrieval system,
or transmitted
in any form
or by any means, electronic,
mechanical,

3. Table of content
1- Respiratory system
- respiratory system function
-respiratory epithelium
2 – ciliated columnar cells
3- Nasal cavity
4- olfactory mucosa
5- histology of bronchial tree
- Bronchus
- bronchioles
6 Alveolus and capillaries
Histology of respiratory system for medical
students
3

4. Histology of respiratory system for medical
students
4

5. Histology
Histology of respiratory system for medical
students
5
Histology is a vast and
complex field, but it provides
valuable insights into the
structure and function of
tissues in various
organisms. It has played a
major role in advancing our
understanding of health,
disease, and biology.

6. Histology of respiratory system for medical
students
6
•Tissue fixation: This
process preserves the tissue
and prevents it from
decomposing.
•Embedding: The tissue is
embedded in a
medium, such as paraffin
wax, to make it easier to cut
into thin sections.
•Sectioning: The tissue is
cut into very thin
sections, typically 5-10
micrometers thick.
•Staining: The sections are
stained with dyes to
highlight specific structures.
techniques used in histology:

7. Histology of respiratory system for medical
students
7
The respiratory system is
essential for life. It provides
your body with the oxygen it
needs to function and
removes the carbon dioxide
that would otherwise build
up and be toxic.

8. Histology of respiratory system for medical
students
8
The respiratory system is a
complex network of organs
and tissues that work
together to allow you to
breathe. Its primary function
is to take in oxygen from the
air and release carbon
dioxide, a waste product of
cellular respiration. The
system is made up of the
following:

9. The system is made up
of the following:
Histology of respiratory system for medical
students
9
•Upper respiratory tract:
• This includes the nose
1. nasal cavity,
2. sinuses,
3. pharynx (throat)
4. And
5. larynx (voice box).
Upper respiratory tract

10. Histology of respiratory system for medical
students
10
Lower respiratory
tract: This includes the
trachea (windpipe)
bronchi, bronchioles, a
nd alveoli air sacs
in the lungs.

11. Histology of respiratory system for medical
students
11
Muscles of
respiration: The
diaphragm and
intercostal muscles help
to expand and contract
the chest cavity
creating the pressure
changes needed for
breathing.

12. Histology of respiratory system for medical
students
12
how the respiratory system
works:
• Inhalation: You breathe in air
through your nose or
mouth. The air passes
through the nasal
cavity, where it is
warmed, humidified, and
filtered. It then travels down
the pharynx and into the
larynx.

13. Histology of respiratory system for medical
students
13
• Gas exchange: The air
travels down the trachea
and into the
bronchi, which branch off
into smaller and smaller
airways called
bronchioles. These
eventually lead to the
alveoli, tiny sacs in the
lungs where gas
exchange takes
place. Oxygen diffuses
from the alveoli into the
bloodstream, while
carbon dioxide diffuses
from the bloodstream into
the alveoli.

14. Histology of respiratory system for medical
students
14
• Exhalation: You breathe
out air through your nose
or mouth. The air travels
back up the airways and
out of the body.

15. Histology of respiratory system for medical
students
15

16. Histology of respiratory system for medical
students
16

17. Histology of respiratory system for medical
students
17

18. Histology of respiratory system for medical
students
18

19. Histology of respiratory system for medical
students
19

20. Histology of respiratory system for medical
students
20

21. Histology of respiratory system for medical
students
21

22. Histology of respiratory system for medical
students
22

23. Histology of respiratory system for medical
students
23

24. Histology of respiratory system for medical
students
24

25. Histology of respiratory system for medical
students
25

26. BRONCHIAL TREE
Histology of respiratory system for medical
students
26
Primary
Secondary
Tertiary

27. Histology of respiratory system for medical
students
27

28. BRONCHIAL TREE
• 1, 2, 3 Bronchi
• Cartilage plates, glands
present, smallest is 5mm,
many lymphocytes present
• Bronchioles
• No cartilage, no glands
• Alveolar Duct
• Alveolar Sac
• Gas exchange
• Alveolus
Histology of respiratory system for medical
students
28

29. HISTOLOGY OF
BRONCHIAL TREE
• Cartilage
• Rings, plates, disappears
Smooth Muscle Layer
Begins in bronchi,
more prominent
in bronchioles
then disappears
1. Epithelium
1. Pseudostratified,
2. Simple columnar,
3. cuboidal,
4. squamous
Histology of respiratory system for medical
students
29

30. Bronchus
Histology of respiratory system for medical
students
30
Cartilage

31. Bronchus
Histology of respiratory system for medical
students
31
Lamina propria

32. Bronchus
Histology of respiratory system for medical
students
32

33. Bronchioles
• > 5mm diameter
• No cartilage or glands in
mucosa
• Epithelium changes from
• pseudostratified to cuboidal
epithelium.
• shortening along the way.
• Only scattered goblet cells
initially.
• Clara cells secrete protective
proteins.
• Lamina propria contains only
• smooth muscle and elastic
fibers.
• Vagas nerve, sympathetic
neurons
Histology of respiratory system for medical
students
33

34. Bronchiole x10
Histology of respiratory system for medical
students
34

35. Bronchiole x40
Histology of respiratory system for medical
students
35

36. Alveolus
Bronchiole
Histology of respiratory system for medical
students
36

37. Location of Gas Exchange
Histology of respiratory system for medical
students
37

38. ALVEOLUS AND CAPILLARY
Histology of respiratory system for medical
students
38

39. GAS EXCHANGE
• Respiratory membrane
• Layers
• Cells present in alveolus
• Simple squamous epithelium
• Other cells in alveolus
• Macrophages
• Surfactant cells
Histology of respiratory system for medical
students
39

40. Histology of respiratory system for medical
students
40
Section of a terminal bronchiole with
a small portion of a
respiratory bronchiole
continuous with an
alveolar duct and many
alveoli. Low magnification.

41. Histology of respiratory system for medical
students
41

42. Histology of respiratory system for medical
students
42
Diagram of a
portion of the
bronchial tree.
Note that the
smooth muscle in
the alveolar duct
disappears in the
alveoli.

43. Histology of respiratory system for medical
students
43
Transition of a terminal
bronchiole into
an alveolar duct (arrow). Note
the Clara cells arrowheads.

44. Respiratory Duct
With Alveoli
Histology of respiratory system for medical
students
44

45. Alveolus
Histology of respiratory system for medical
students
45

46. Alveolar Sac
Histology of respiratory system for medical
students
46

47. Blood Vessel in Lung
Histology of respiratory system for medical
students
47

48. Alveolus with Capillary
Histology of respiratory system for medical
students
48

49. Interface
between
capillary
and alveolus
Histology of respiratory system for medical
students
49

50. Interface Between Capillary, Alveolus
Histology of respiratory system for medical
students
50

51. Alveoli and interalveolar septum
showing capillaries and epithelial
. Cells type I and II
Histology of respiratory system for medical
students
51

52. Cells Located in Alveolus
• Type I alveolar cells
• Simple squamous cells
• Type II cells
• Surfactant
• Macrophages (dust cells)
Histology of respiratory system for medical
students
52