Module 10 Respiratory System Flashcards
Functions of Respiratory System (hint- 5 main functions)
- Transport of oxygen
- Remove carbon dioxide.
- Control blood acidity (pH)
- Temp regulation
- Defense
Anatomy of Respiratory System
(Pharynx, Larynx, Trachea)
PLT
Characteristics of Capillaries that maximize gas exchange (3)
- Thin endothelial walls
- large total cross-sectional area
- very low blood velocity
Pressures of the Lungs
Intrapleural- Outside the lungs (756 mmHg pressure)
Intrapulmonary- Inside the lungs (760 mmHg pressure)
Intrapleural Pressure/ Space includes two membranes
- (The parietal pleura): Lines and sticks to the ribs.
- (The visceral pleura): Surrounds and sticks to the lungs.
Transpulmonary Pressure
Difference between the alveolar and intrapleural pressures
What would happen if both intrapleural and intrapulmonary pressures were equal
The lung would collapse producing pneumothorax
Explain Boyles Law of Ventilation
- When you inhale, the volume of air in your lungs increase, but the pressure decreases.
- When you exhale, the volume of air in your lungs decrease, but the pressure increases.
Explain mechanisms of expiration at rest (3 things)
- Diaphragm and external intercostal muscles relax.
- Lungs to recoil to their original size.
- Volume decreases, the alveolar (intrapulmonary) pressure increases above atmospheric pressure.
- The pressure gradient is now reversed (high inside at 761 mmHg and low outside at 760 mmHg).
Explain mechanisms of expiration during exercise
- Air must be forced out of the lungs.
- Requires contraction of the abdominal muscles and the internal intercostal muscles of the ribs.
- When these muscles contract, they further decrease the volume of the lungs.
- Creating a larger pressure gradient (much higher on the inside at 763 mmHg than outside at 760 mmHg.
What is pulmonary compliance?
- Stretchability of the lungs—the more stretchable, the more compliant.
- Defined as the volume change that occurs because of a change in pressure.
- Determines ease of breathing.
- Lung that has decreased compliance is difficult to inflate, one with high is easy to inflate but difficult to deflate.
Give the equation of pulmonary compliance
Compliance= Volume Change/ Pressure Change
What are the two major factors of Pulmonary compliance?
- Amount of elastic tissue (in alveoli, blood vessels, bronchi)
- Surface tension of film of liquid lining alveoli
What does pulmonary fibrosis cause to compliance?
It decreases the compliance
What does normal aging and pulmonary emphysema cause to compliance?
Causes increase in compliance.
What is pulmonary surfactant and how does it affect compliance? (Water droplet reference)
- Increases compliancy of lungs (Helps people breathe easier).
- Lipoprotein substance produced by type II (or great) alveolar cells and consists mostly of phospholipids.
- The forces will now be equal in every direction and the water drop will flatten out due to the decreased surface tension.
What is a spirometer used to measure?
Lung volumes and capacities.
List the four basic lung volumes and explain each of them.
- Tidal volume: The volume of air entering or leaving the lungs during one breath at rest = (500 ml)
- Inspiratory reserve volume: The maximum amount of air that can enter the lungs in addition to the tidal volume (2500 ml)
- Expiratory reserve volume: The maximum amount of air that can be exhaled beyond the tidal volume (1000 ml)
- Residual volume: The remaining air in the lungs after a maximal expiration (1200 ml)