Nittiy gritty facts on exam 1 Flashcards
How does the air change as you increase in elevation?
Air density (amount/volume) is highest @ the earth’s surface & decreases w/ altitude, BUT the composition of gas does NOT change w/ altitude in a dry gas
How does altitude affect oxygen delivery?
As altitude increases, PB decreases, so the PO2 will decrease which limits the ability of the body to deliver O2 to tissues
How does altitude affect carbon dioxide production?
It doesn’t
How is temperature and solubility related?
Inversely
Where is the greatest resistance in the airways?
5-7th generation bronchioles;
After this point, net resistance is smaller because of combined surface area of bronchioles after this point
What is spirometry? What can it measure? Not measure?
Measures lung volumes; Can measure everything but RV, FRC and TLC
What is compliance?
Change in volume / Change in pressure
Discuss Restrictive Abnormalities
- Decrease in lung compliance requires larger distending pressure
- Hallmarks are decreased FVC, RV but no decrease in FEV1
What are the hallmarks of an obstructive abnormality?
Decreased FEV1, FEFmax, FEF25-75
Describe a simple fixed obstruction
Acute bronchospasm, inhalation of foreign object
Airways narrow during both inspiration and expiration
Describe an intra-thoracic variable obstruction and extra thoracic
Airways compressed during expiration; inspiration
Discuss Emphysema
- Fewer and larger alveoli
- Very compliant lungs (barrell chested)
- Air trapping in lungs causes increase in RV
Why is alveolar oxygen less than atmospheric oxygen?
Incoming air is humidified
Incoming air is warmed
O2 is constantly being removed from incoming air
Why must alveolar oxygen be greater than 100 mmHg?
To keep arterial oxygen in normal range
What are some causes of hypoxemia?
- Low alveolar ventilation; breath holding, chemorecptor malfunction
- Low PO2 inspired air; high altitude, rebreathing exhaled air
