2. Respiratory System
Dr. Jack L. Haar

3. Functions of Respiratory System
Transport air to and from lungs
Maintains airway patency
Regulates air temperature
Humidifies air
Decreases air velocity
Cleanses air
Gaseous exchange
Olfaction
Phonation

4. MAJOR SUBDIVISIONS
– Extrapulmonary portion
– Intrapulmonary portion

5. Extrapulmonary portion
1. Nasal cavity
Nasal
2. Pharynx Oral
Laryngeal
3. Larynx
4. Trachea
5. Primary bronchi

6. Extrapulmonary portion
1. Nasal cavity
Nasal
2. Pharynx Oral
Laryngeal
3. Larynx
4. Trachea
5. Primary bronchi

7. MAJOR SUBDIVISIONS
– Extrapulmonary portion
– Intrapulmonary portion

8. Intrapulmonary portion
Secondary
bronchi
Larynx
Trachea
1. Secondary bronchi
2. Bronchioles (and
terminal bronchioles)
3. Respiratory bronchioles
4. Alveolar ducts
5. Alveoli

9. Intrapulmonary portion
1. Secondary bronchi
2. Bronchioles (and
terminal bronchioles)
3. Respiratory bronchioles
4. Alveolar ducts
5. Alveoli

10. Classification by function: Conducting portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles (and
terminal bronchioles)

11. 1. Respiratory bronchioles 2. Alveolar ducts 3. Alveolar sacs
Classification by function:
Respiratory portion
1. Respiratory bronchioles
2. Alveolar ducts
3. Alveolar sacs
4. Alveoli
Terminal
bronchiole RB AS RB AD
Alveoli

12. Histology overview of respiratory passageways
Mucosa: epithelium, lamina propria and muscularis mucosa
Epithelium: pseudostratified columnar epithelium with cilia and goblet cells = Respiratory epithelium

13. Layers of “typical” conducting passageway
Lamina propria
Vascularized
Longitudial arranged elastic fibers
Deepest layer
Elastic lamina OR
Muscularis mucosae OR
Neither

14. Submucosa – connective tissue layer; contains mixed (mucous and serous
Submucosa – connective tissue layer; contains mixed (mucous and serous secreting glands in larger passageways) Bone or Cartilage – present to level of bronchioles where it drops out Adventitia - connective tissue

15. TRANSITIONS – Layers become thinner and drop out – Epithelium
- decreases in height
- goblet cells drop out
- cilia disappear
– Mixed glands drop out
– Cartilage drops out

16. Wall of alveolus where gas exchange occurs
(Inter)alveolar Septum
Simple squamous
epithelium
Connective tissue core
Reticular + elastic fibers
and CT cells
Capillaries
Alveolus
Cap
Simple
squamous
epithelium

18. Variation on this layering theme

19. Conducts air from exterior to where
MAJOR SUBDIVISIONS
– Conducting portion
– Respiratory portion
Conducts air from exterior to where
gas can be exchanged,
i.e., alveoli

20. Extrapulmonary of Conducting Portion
Nasal cavities
Non-olfactory region
Vestibules – transition from skin to respiratory epithelium
Nasal fossae
Respiratory epithelium,
Abundant blood vessels
Muscularis mucosae absent
Bones and cartilage for patiency
Non-olfactory region

21. Nasal cavity Non-olfactory region Resp. epith. Lam. propria Submucosa
(some cartilage)
Bone
NO musc. muc.

22. Nasal cavity
Olfactory region

23. Olfactory region Superior concha
U-shaped area in posterior, superior regions of nasal fossae
Superior concha
Non-olfactory
region
Olfactory
region

24. Nasal cavity
“Typical” nasal mucosa
Olfactory mucosa

25. Olfactory cells: bipolar neurons, single dendrite extends to surface
terminates in olfactory vesicle, non-motile cilia extend over surface
Supporting cells and basal cells as reserve
Olfactory
epithelium
“Typical” nasal mucosa
Olfactory mucosa

26. Nasal cavity Olfactory mucosa “Typical” nasal mucosa
Muscularis mucosae not present
Lamina propria blends with submucosa
Bowmans glands flush odorants
Serous glands
of Bowman

27. Pharynx
Nasal
Oral
Laryngeal

28. Extrapulmonary Components of Conducting Portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles and
terminal bronchioles

30. Larynx
Extrapulmonary-Conducting

31. Larynx Extrapulmonary-Conducting 1. Epiglottal cartilage
2. Thyroid cartilage
3. Cricoid cartilage
4. Tracheal cartilages
5. Vestibule
6. False vocal fold
7. Ventricle
8. True vocal fold with
vocal ligament
(dense reg elastic CT)
9. Vocalis muscle 2 3 9 7 6 1 5 8 4
Trachea

32. Stratified squamous moist epiglottis and true vocal fold
Larynx
Extrapulmonary-Conducting
MOST of mucosa is a
“typical” respiratory mucosa
with NO musc. mucosae.
False
vocal
fold
EXCEPTIONS:
Stratified squamous moist
epithelium covering
epiglottis and true vocal fold VL VM

33. Mixed glands in submucosa Cartilage for patency
Thyroid and cricoid are hyaline
Epiglottis and smaller cartilages are elastic
Vocal apparatus
False vocal folds
Ventricle
True vocal folds
Vocal ligament - dense regular elastic CT
Vocalis muscle – skeletal muscle

34. Extrapulmonary of Conducting Portion 1. Nasal cavity 2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles and
terminal bronchioles

35. Trachea and Primary Bronchi are identical
Mucosa

36. Respiratory epithelium with prominent basement membrane
Longitudinal section
Esophagus
Trachea
LUMEN

37. Elastic lamina of longitudinally arranged elastic fibers
Mixed glands in submucosa
Cartilage rings for patency

38. Intrapulmonary Components of Conducting Portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles and
terminal bronchioles

39. Secondary bronchus Surrounded by ALVEOLI 2nd B Bronchus Bronchiole 2nd
Pulm BV
Pulm BV
Bronchiole
2nd
Bronchus
Surrounded by
ALVEOLI B

40. Secondary bronchus Surrounded by ALVEOLI Mucosa Resp epithelium
Lamina propria
Musc. mucosae
Submucosa
Mixed glands
Cartilage plates
Adventitia
Cartilage

41. Intrapulmonary of Conducting Portion
1. Nasal cavity
2. Pharynx
3. Larynx
4. Trachea
5. Primary bronchi
6. Secondary bronchi
7. Bronchioles and
terminal bronchioles

42. Walls of Bronchi and Bronchioles continue to decrease in size

43. Transition from secondary bronchus to bronchiole

44. Bronchioles No mixed glands No cartilage
Epithelium: respiratory in largest bronchioles
Epithelium: simple columnar with cilia in terminal bronchioles

45. Terminal bronchiole
Clara cells present among simple columnar epithelial cells
Dome-shaped
Non-ciliated with granules
Secretions lower surface tension

46. Clara cells

47. Lamina propria: longitudinally arranged elastic fibers
Muscularis mucosae: smooth muscle at greatest thickness
Submucosa: no glands, no cartilage, no bone
Smooth
muscle
Elastic
fibers

48. MAJOR SUBDIVISIONS – Conducting portion – Respiratory portion
Where gas exchange
actually occurs,
i.e., alveoli

49. Transitions
Bronchiole to
Terminal
bronchiole
Respiratory B TB RB

50. Transitions of bronchioles
Conducting Respiratory
portion portion

51. Respiratory bronchiole
Continues to decrease in diameter and thickness

52. Respiratory bronchiole
Simple cuboidal epithelium
Elastic fibers in lamina prop.
Muscularis mucosa of smooth muscle
Alveoli bulge off of wall

53. Alveolar duct Alveoli increase in number Wall is reduced to rings RBAD A
Alveoli increase in number
Wall is reduced to rings

54. Alveolar duct
Alveoli increase in number
Wall is reduced to rings

55. Alveolar sac
Multiple alveoli
No wall of cuboidal cells

56. Alveoli Thin walled chambers, 200μm diameter, for gas exchange
Interalveolar septum separates alveoli

57. Interalveolar septum CT core Elastic/reticular fibers Fibroblasts
Macrophages
Capillaries which form 80% of alveolar surface

58. Interalveolar septum CT core Elastic/reticular fibers Fibroblasts
Macrophages
Capillaries which form 80% of alveolar surface

59. Epithelium lining alveoli
Pulmonary epithelial cells (Small alveolar or type I)
Lines 95% of alveolar surface

60. Epithelium lining alveoli
Pulmonary epithelial cells (Small alveolar or type I)
Lines 95% of alveolar surface

61. Epithelium lining alveoli
Septal cells (Great alveolar or type II)
Regenerate type I and type II cells

62. Epithelium lining alveoli
Septal cells (Great alveolar or type II)
Regenerate type I and type II cells
Mitochondria, RER, Golgi
Vacuoles containing the phospholipid surfactant
Surfactant lowers surface tension of alveoli

63. Epithelium lining alveoli
Surfactant
Extracellular fluid layer lining alveoli
Lowers surface tension, preventing collapse of alveoli during expiration
Covers underlying aqueous hypophase
Appears during last weeks of gestation
Respiratory distress syndrome or hyaline membrane disease may result

64. Macrophages May be found in the CT core of interalveolar septum
Alveolar macrophages are in the alveolar space

65. Kohn’s pores Opening in interalveolar septa
Equalize pressure between alveoli
Facilitate transfer of bacteria between alveoli

66. Air - blood barrier Pulmonary epithelial cell and its basal lamina
Capillary endothelial cell and its basal lamina

67. Air - blood barrier Pulmonary epithelial cell and its basal lamina
Capillary endothelial cell and its basal lamina

68. Air - blood barrier Pulmonary epithelial cell and its basal lamina
Capillary endothelial cell and its basal lamina

69. Pleura Mesothelium with C.T. Visceral layer Parietal layer Function
Lubrication

70. Pleura
Alveolus

71. Vascular supply to lungs
Blood to and from alveoli
Pulmonary artery
Adjacent to bronchial tree

72. Vascular supply to lungs
Blood to and from alveoli
Pulmonary artery
Adjacent to bronchial tree
Carries unoxygenated blood

73. Vascular supply to lungs
Blood to and from alveoli
Capillary plexus in interalveolar septa

74. Pulmonary veins
Travel away from bronchial tree
Carry oxygenated blood

75. Nutrient vessels Bronchial arteries
Vessels within wall of bronchial tree
Supply nutrients to passageways themselves

76. Nutrient vessels Bronchial arteries
Vessels within wall of bronchial tree
Supply nutrients to passageways themselves

77. Pathology Effects of smoking

78. Running the numbers web site

79. Pathology Nasal sinues

80. Emphysema

81. Asthma

82. Chronic bronchitis

83. Pneumonia

88. Functions of Respiratory System
Transport air to and from lungs
Maintains airway patency
Regulates air temperature
Humidifies air
Decreases air velocity
Cleanses air
Gaseous exchange
Olfaction
Phonation

89. TB or not TB?
That is the congestion.
Consumption be done about it?
Of cough, Of cough,
But it will take a lung, lung time!
-Walter Shakespear

90. http://www. path. uiowa. edu/virtualslidebox/ Table of Contents
Table of Contents Lung and respiratory tract Lung (3 slides)
Respiratory
Lung
Trachea I
Trachea II