Resp Flashcards
What are the main functions of the respiratory system?
Gas exchange, acid-base balance, protection, communication
How does the respiratory system contribute to energy production?
Delivers O2 for ATP production and removes CO2 waste
What is the difference between external and internal respiration?
External: gas exchange in lungs; Internal: cellular respiration
What is the main site of gas exchange?
Alveoli
What maintains airway patency in the conducting zone?
C-shaped cartilage rings
What are Type I and Type II alveolar cells?
Type I: gas exchange; Type II: surfactant secretion
What is anatomical dead space?
Air in the conducting zone that does not participate in gas exchange
How does airway resistance vary?
It is inversely related to airway radius and airflow becomes more laminar down the tract
What are the primary lung volumes?
TV, IRV, ERV, RV
What are lung capacities?
VC, TLC, IC, FRC (combinations of primary volumes)
What is Boyle’s Law?
Pressure inversely proportional to volume
What is transpulmonary pressure?
Difference between alveolar and intrapleural pressure (P_T = P_A - P_ip)
How do the pleural membranes aid lung expansion?
They stick the lungs to the chest wall via cohesive pleural fluid
What is the role of surfactant?
Reduces surface tension, prevents alveolar collapse, increases compliance
What is lung compliance?
Change in lung volume for a given change in pressure; reflects distensibility
What causes Infant Respiratory Distress Syndrome?
Lack of surfactant in premature babies
What is pulmonary ventilation?
Total air moved into/out of lungs per minute
What is alveolar ventilation?
Fresh air reaching alveoli per minute, available for gas exchange
What is dead space volume?
Volume of air not involved in gas exchange (~150 mL)
What affects alveolar ventilation more: rate or depth?
Depth of breathing, due to impact of dead space
What happens to PO2 and PCO2 during hyperventilation?
PO2 ↑ to ~120 mmHg, PCO2 ↓ to ~20 mmHg
What happens to PO2 and PCO2 during hypoventilation?
PO2 ↓ to ~30 mmHg, PCO2 ↑ to ~100 mmHg
What is the partial pressure of oxygen in alveoli under normal conditions?
100 mmHg
What law describes gas diffusion in lungs?
Dalton’s Law and simple diffusion principles
What factors influence gas diffusion across alveoli?
Partial pressure gradient, solubility, surface area, membrane thickness
What is the difference between pulmonary and bronchial circulation?
Pulmonary: gas exchange; Bronchial: tissue nourishment
