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

Previous problemNext problem

Struggling with Anatomy & Physiology?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

What causes air to move into the lungs during inspiration?

Closure of the epiglottis

A decrease in intrapulmonary pressure relative to atmospheric pressure

Contraction of the abdominal muscles

An increase in blood pressure within the pulmonary arteries

Previous problemNext problem

Verified step by step guidance

Understand the process of inspiration: During inspiration, air moves into the lungs due to a pressure gradient created between the atmosphere and the lungs. This occurs when the pressure inside the lungs (intrapulmonary pressure) becomes lower than the atmospheric pressure.

Identify the role of the diaphragm and external intercostal muscles: The diaphragm contracts and moves downward, while the external intercostal muscles contract to lift the rib cage. This increases the volume of the thoracic cavity.

Apply Boyle's Law: Boyle's Law states that pressure and volume are inversely related. As the thoracic cavity's volume increases, the intrapulmonary pressure decreases, creating a pressure gradient where air flows from the higher atmospheric pressure into the lower intrapulmonary pressure.

Clarify why the other options are incorrect: Closure of the epiglottis prevents food from entering the airway, not air movement. Contraction of abdominal muscles is associated with forced expiration, not inspiration. Blood pressure in pulmonary arteries is unrelated to the mechanics of air movement into the lungs.

Summarize the correct mechanism: Air moves into the lungs during inspiration due to the decrease in intrapulmonary pressure relative to atmospheric pressure, facilitated by the contraction of the diaphragm and external intercostal muscles.