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

Why does air flow into the lungs during inspiration?

Because the diaphragm relaxes, decreasing thoracic volume and increasing pressure inside the lungs.

Because the diaphragm contracts, increasing thoracic volume and decreasing pressure inside the lungs.

Because the intercostal muscles contract, decreasing thoracic volume and increasing pressure inside the lungs.

Because the intercostal muscles relax, increasing thoracic volume and decreasing pressure inside the lungs.

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Verified step by step guidance

Understand the basic mechanics of breathing: During inspiration, air flows into the lungs due to a pressure difference between the atmosphere and the thoracic cavity.

Recognize the role of the diaphragm: During inspiration, the diaphragm contracts and moves downward, which increases the volume of the thoracic cavity.

Apply Boyle's Law: As the volume of the thoracic cavity increases, the pressure inside the lungs decreases. This creates a pressure gradient where the atmospheric pressure is higher than the pressure inside the lungs.

Consider the role of intercostal muscles: The external intercostal muscles also contract during inspiration, lifting the rib cage and further increasing thoracic volume.

Conclude the process: The decrease in intrapulmonary pressure relative to atmospheric pressure causes air to flow into the lungs until the pressures equalize.