Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

22. The Respiratory System

Introduction to Lung Physiology

Anatomy & Physiology

22. The Respiratory System

Introduction to Lung Physiology

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Multiple Choice

Which of the following determines the direction of respiratory gas movement in the lungs?

The thickness of the alveolar membrane

The number of red blood cells

Partial pressure gradients of the gases

The temperature of inspired air

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Verified step by step guidance

Understand the concept of respiratory gas exchange: Gas exchange in the lungs occurs due to diffusion, where gases move from areas of higher partial pressure to areas of lower partial pressure.

Define partial pressure: Partial pressure refers to the pressure exerted by a single type of gas in a mixture of gases. In the lungs, oxygen and carbon dioxide have specific partial pressures in the alveoli and blood.

Identify the role of partial pressure gradients: The direction of respiratory gas movement is determined by the difference in partial pressures (gradient) between the alveoli and the blood. Oxygen moves from the alveoli (higher partial pressure) to the blood (lower partial pressure), while carbon dioxide moves from the blood (higher partial pressure) to the alveoli (lower partial pressure).

Eliminate irrelevant factors: The thickness of the alveolar membrane, the number of red blood cells, and the temperature of inspired air do not directly determine the direction of gas movement. These factors may influence the efficiency of gas exchange but not the direction.

Conclude that partial pressure gradients are the key determinant: The movement of gases in the lungs is driven by the partial pressure gradients of oxygen and carbon dioxide, ensuring proper gas exchange during respiration.