Respiratory practice questions Flashcards
Wha is the effect of HIF-1 (hypoxia inducible factor 1) under hypoxic conditions?
- Upregulates glucose transporters
- Inhibits pyruvate dehydrogenase (PD kinase inactivates PDH)
- This upregulates lactic dehydrogenase and BNIP3 and BNIP3L —> trigers mitochondrial autophagy
- Glycolysis is promoted and TCA inhibited to prevent toxicity from ROS
What changes in a fibrotic lung?
- Decrase in FRC
- Increase in FEV1
What factors influence Zone 2 of lungs?
Coupling between metabolic rate and ventilation best discribed as?
PaCO2
What does qty of gas diffused into a liquid over given time period depends on?
- Diffusion coefficient of gas
- Temperature
- Solubility coefficient
*Partial pressure gradient, not concentration gradients
What influences O2 consumption?
- Concentration of inspired O2
- Pulmonary ventilation
- Plumonary extraction coefficient
- NOT resp. exchange ratio
Respiratory quotient?
Relationship between CO2 produciton and O2 consumption at tissue level
Why is gas echange more efficieny in birds than mammals?
- Air sacs
- No diaphragm
- High body temperature
- Cross-current for gas exchange
How does the work of breathing change when Breathing faster?
- Increased total work of breathing
Abdominal muscles for?
- Cough
- Forced expiration
How are the different pressures at the end of expiration when the subject relaxes?
All positive pressure expect pleural pressure
During quiet breathing, what does the rate of pulmonary airflow depend on?
- Pleural pressure
- Alveolar pressure
- Airway resistance
What is the maximum ventilatory ventilation limited by?
Expiratory flow-volume curve
- NOT inspiration or max muscle force
How are slow adapting stretch receptors related to difference between inspiration vs expiration flow?
SAR increase muscle recruitement during inspiration by sensing stretch (faster inspiration)
Expiration = passive recoil
When is the lowest PCO2 expired during expiration?
During 1st part (dead space)
