1. Respiratory System b
Chapter 24

4. Lungs Gas exchange organs
Delicate structure of Airways, Alveoli, capillaries
Right lung
3 lobes
Superior, middle, inferior
Left lung
2 lobes
Superior, inferior
Cardiac notch accommodates heart
Located in separate pleural cavities

5. Lung Lobes

6. Lung

9. Alveoli Structure 3 cell types Epithelial Cells (type I)
Simple Squamous
Alveolar macrophages
Phagocytic WBC
Engulf inspired particles (dust)
Surfactant secreting cells (Type II)
Secrete surface active agent
Surfactant
Decreases intra-alveolar surface tension
Prevents alveolar collapse

10. Alveoli Structure

13. Type I
Exchange gas with capillaries

14. Type II aka Surfactant Secreting Cell
Regeneration & surfactant production

15. Surfactant Secreting Cell

17. Surfactant

19. Macrophages

20. Macrophages “Eat” Debris & Bacteria
Macrophages eating soot

21. Macrophage
Alveolar Pores

22. Alveoli Function Simple squamous epithelium
Provide favorable diffusion surface
Small diffusion distance
Large surface area
300 million alveoli produce ~760 sq ft
Contribute to respiratory membrane

24. Gas Exchange
Gas exchange between air in alveoli & blood in capillaries
High blood perfusion to lungs
Alveolar capillaries surround alveoli

25. Highly Vascularized

26. Alveolar Capillaries

27. Alveolar Capillaries

29. Figure: 14-11br
Title:
Respiration.
Caption:
Bottom right: external respiration.

30. Respiratory Membrane 2 cell layers of simple squamous
Alveolar epithelial cells
Capillary endothelial cells
Total diffusion distance
~0.1 – 1.5 microns
Efficient diffusion distance
Carbon dioxide diffuses into alveoli
Oxygen diffuses out of alveoli

31. Diffusion distance

32. Respiratory Membrane

35. Respiration Breathing Involuntary contraction of diaphragm
Cycle of inhalation & exhalation
Involuntary contraction of diaphragm
Driven by change in pressure
Body creates negative pressure in body cavity
Regulated chemically
Amounts of CO2 in blood stream

36. Respiration Ventilation Systemic respiration Cellular respiration
Movement of air in & out of lungs
Systemic respiration
Exchange of gas between inhaled air & blood
Cellular respiration
Cell use of O2 to make ATP

37. Ventilation Involves changes in pressure to move air in & out
Respiratory muscles
Diaphragm
Increases volume of thoracic cavity by “dropping” floor
External intercostal
Elevate ribs expanding chest cavity
Internal intercostal
Depress ribs to reduce volume of thoracic cavity

38. Diaphragm

39. Diaphragm important in respiration

41. Muscles Associated with Breathing

43. Serous membranes Parietal pleura Visceral pleura Ventilation
Lines pleural cavity
Visceral pleura
Covers lung
Ventilation
Movement of chest wall
Membranes adhere to each other
Movement of chest wall “pulls” lungs open

44. Serous Membranes

45. Serous membranes adhere via cohesion

46. Respiration Inhalation Exhalation Rib cage expands- increases volume
Diaphragm contracts- increases volume
Creates negative pressure in lungs
Air rushes in
Exhalation
Rib cage contracted- decrease volume
Internal intercostals contract
Inhalation muscles relax
Diaphragm relaxes- decrease volume
Increases pressure IN lungs
Air rushes out

47. Inhalation

48. Exhalation

49. Respiration
- blank

51. Systemic Respiration Exchange of gas across respiratory membrane
Passive transport down concentration gradient

53. Neural control Blood gas levels monitored by breathing control centers
Adjust breathing to meet body’s needs

54. Smoking & You

55. Smoking is the leading cause of death in America
Figure: 14A-01a
Title:
Cigarette smoking reduces life expectancy.
Caption:
(a) Smoking causes more than 400,000 deaths each year in the United States, more people each year than the combined number of deaths due to AIDS, alcohol, drugs, car accidents, murder, and suicide. These data are from a report from the Centers for Disease Control and Prevention in The number of deaths from cigarette smoking have increased since then, but the relative importance of each cause of death remains similar.

56. Lung disease Lining of respiratory surface- delicate
Molecules bind & impair function
Protected by
Mucus
Cilia
Lung cancer
Emphysema

60. Emphysema
Alveoli over-inflate because of a breakdown of alveolar walls
Resulting decrease in respiratory function
3 million Americans
15th most common chronic condition
Leading cause
Cigarette smoking

61. Emphysema

62. Emphysema

64. Smoking is BAD! Figure: 14A-01b Title:
Cigarette smoking reduces life expectancy.
Caption:
(b) A study published in 2004 followed nearly 35,000 male British doctors for 50 years. On average, the cigarette smoking cut 10 years off a smoker's life. A quarter of the lifetime smokers died before age 70.

65. Smoking Results in all kinds of BAD days!
Table: 14A-T01
Title:
Types of increased cancer risk due to smoking.
Caption:

66. Don’t Despair… Figure: 14A-08 Title: Comparing lung cancer deaths.
Caption:
A comparison of lung cancer deaths among lifetime nonsmokers, ex-smokers, and continuing smokers. Quitting dramatically reduces a smoker's risk of death due to lung cancer.

67. Pollution and Your Lungs