1. Biology 212 Anatomy & Physiology
Dr. Thompson
Respiratory System

2. Functions of Respiratory System
Ventilation:
Gas Exchange:
Gas Transport:

3. Organs of Respiratory System
Nasal Cavity
Pharynx
Larynx
Trachea
Bronchi
Lungs
Air Blood
Smaller bronchi Branches of pulmonary arteries
Bronchioles Arterioles
Alveolar ducts Capillaries
Alveoli Venules
Branches of pulmonary veins

6. Nasal Cavity:

11. Inhaled air passes from nasal
cavity into pharynx.
Three regions:
Nasopharynx
Oropharynx
Laryngopharynx

12. Functions of Larynx:

13. Structure of Larynx:
Nine cartilages connected by muscles & ligaments

14. Structure of Larynx: Nine cartilages: 3 large unpaired:
6 smaller paired:
Anterior View
Posterior View

15. Anterior Posterior Midsagittal (Section)
Superior

16. Vocal cords (also called vocal folds or vocal ligaments)

17. Vocal cords (also called vocal folds or vocal ligaments) are strands of dense regular connective tissue running anteriorly from arytenoid cartilages to thyroid cartilage.
Air moving between them cause them to vibrate.

18. Trachea:
Cricoid Cartilage
Primary Bronchus

19. Trachea:

20. Cross section of neck at level of vertebra cervical 6

21. Lungs:
Occupy most of thoracic cavity

22. Lungs:

23. Lungs:

25. Lungs:

26. Lungs:

27. Lungs:

28. Lungs:

29. Trachea
Primary bronchi
Secondary bronchi
Tertiary bronchi
(smaller branches)
(bronchioles)
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveoli

30. Trachea
Primary bronchi
Secondary bronchi
Tertiary bronchi
(smaller branches)
(bronchioles)
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveoli
Conducting Zone
Respiratory Zone

31. Alveoli:

32. As the bronchi branch and divide, so do the pulmonary arteries and pulmonary veins which accompany them.
At the end, each alveolus is
surrounded by many capillaries
for the exchange of gasses
between air (in the alveolus)
and blood (in the capillaries).

33. This air (in the alveolus) and blood (in the capillaries)

34. Let’s return to ventilation:

35. Air pressure is measured

36. Terminology you need to know:
Atmospheric pressure
Intrapulmonary pressure
Intrapleural pressure

38. Proper ventilation requires that the lungs also expand each time the thoracic cavity expands.

39. Respiratory Volumes:
TIDAL VOLUME:

40. Respiratory Volumes:
EXPIRATORY RESERVE VOLUME:

41. Respiratory Volumes:
INSPIRATORY RESERVE VOLUME:

42. Respiratory Volumes:
RESIDUAL VOLUME:

43. Respiratory Volumes:
VITAL CAPACITY:

44. Respiratory Volumes:
TOTAL LUNG CAPACITY:

45. Note that all of the air which enters your nose does not reach your alveoli.

46. Gas Exchange: Movement of specific gases:
a) From a mixture of gases into a liquid
(e.g. oxygen moves from air in the alveoli into blood in the capillaries)
b) From a liquid into a mixture of gases
(e.g. carbon dioxide moves from blood in the capillaries
into air in the alveoli)
From one liquid into another liquid
(e.g. oxygen leaves the blood and diffuses into extracellular fluid, while carbon dioxide moves from the extracellular fluids into the blood.

48. Dalton’s Law:

49. Atmospheric Air:
Nitrogen = 78%
Oxygen = 21%
Water = 0.5%
Carbon dioxide = 0.04%
Other gases = 0.46%
Total = 100%
This mixture of gases exerts a total pressure of approximately 760 mm Hg

50. Henry’s Law:

51. (How much of a gas dissolves in a liquid can only be changed by changing its partial pressure, which can only be changed by changing its concentration.)
Thus:

52. Example #1:
Suppose you have air which is
78% Nitrogen
20% Oxygen
1% Water
1% Carbon dioxide
and you measure how rapidly oxygen diffuses from this air to blood
Then, you change the composition of the air to
75% Nitrogen
14% Oxygen
5% Water
6% Carbon dioxide
How will this affect how much oxygen diffused from the air to the blood?

53. Example #2:
Suppose you have air which is
78% Nitrogen
20% Oxygen
1% Water
1% Carbon dioxide
and you measure how rapidly oxygen diffuses from this air to blood
Then, you change the composition of the air to
69% Nitrogen
20% Oxygen
5% Water
6% Carbon dioxide
How will this affect how much oxygen diffused from the air to the blood?

54. Realize:
The composition of air in alveoli does not equal the composition of air in the atmosphere. . b) c)

55. Inspired air: Alveolar air:
78.6% Nitrogen % Nitrogen
20.8% Oxygen % Oxygen
0.5% Water % Water
0.04% Carbon dioxide % Carbon dioxide

56. Recall:
Gas exchange has four parts:
Oxygen moves from air to blood in lung
Carbon dioxide moves from blood to air in lung
Oxygen moves from blood to extracellular fluids in
consumer tissues
Carbon dioxide moves from extracellular fluids to blood
in consumer tissues
Fortunately: All of these gas movements are governed by the same laws of physics (Dalton’s and Henry’s laws).
That is: movement of a gas from one place to another depends on its concentrations in the two places and on its solubility.