1. Features of Gas Exchange Surfaces:
- Large Surface Area:
- Facilitates increased gas exchange efficiency.
- Thin Surface:
- Shortens the diffusion distance for gases.
- Good Blood and Air Supply:
- Ensures effective exchange between respiratory surfaces and blood.
2. Percentages of Gases in Atmospheric Air:
- Nitrogen (N₂): ~78%
- Oxygen (O₂): ~21%
- Carbon Dioxide (CO₂): ~0.04%
3. Inspired and Expired Air Differences:
- Inspired Air: Higher oxygen, lower carbon dioxide.
- Expired Air: Lower oxygen, higher carbon dioxide.
4. Identification of Respiratory System Components:
- Larynx, Trachea, Lungs, Bronchi, Bronchioles, Alveoli, Associated Capillaries.
5. Characteristics and Role of Alveoli in Gas Exchange:
- Characteristics:
- Thin-walled sacs with a rich capillary network.
- Role:
- Facilitate efficient exchange of oxygen and carbon dioxide between air and blood.
6. Identification of Thoracic Components:
- Ribs, Internal and External Intercostal Muscles, Diaphragm.
7. Role in Breathing (Volume and Pressure Changes):
- Ribs and Muscles:
- Expand and contract the thoracic cavity.
- Diaphragm:
- Contracts (flattens) during inhalation, increasing thoracic volume.
- Relaxes during exhalation, reducing thoracic volume.
- Result:
- Volume changes cause pressure changes, facilitating air movement.
8. Effect of Physical Activity on Breathing:
- Increased Rate and Depth:
- Meets increased oxygen demands during activity.
- Enhances removal of carbon dioxide produced.
9. Role of Goblet Cells, Ciliated Cells, and Mucus:
- Goblet Cells and Mucus:
- Produce mucus to trap particles and pathogens.
- Ciliated Cells:
- Move mucus upward, aiding in its removal from the respiratory system.
Understanding the features of gas exchange surfaces, respiratory system components, and the mechanisms of breathing is crucial for comprehending how the human body efficiently exchanges gases with the environment.
