Respiratory Physiology Flashcards
Volume of air inspired or expired with each normal breath?
Tidal volume
Air that cans still be breathed in after normal inspiration?
Inspiratory Reserve Volume
Air that can still be breathed out after a normal expiration?
Expiratory Reserved Volume
Air in the lung after maximal expiration?
Residual Volume
Air that can be breathed in after normal expiration?
Inspiratory Capacity
Air that remains in the lungs after a normal expiration?
Functional Residual Capacity
Marker of lung function?
Functional Residual Capacity
Maximum volume of gas that can be expired after a maximal inspiration?
Vital Capacity
Volume of gas present in the lungs after a maximal inspiration?
Total Lung Capacity
Volume of air utilized for continual gas exchange to occur between breaths?
Residual Volume
Lung volume that can not be measured by spirometry?
Residual Volume
What is the effect on resistance and airflow if there’s a decreased airway radius by a factor of 4 ?
By the Poiseuille Law, radius is raised to the fourth power.
-Resistance will increase by a factor of 256 and airflow will decrease by a factor of 256. (Poiseuille Law)
What lung disease?
Low FEV1
Low FVC
FEV1<FVC 📍
High FRC 📍
Obstructive Lung Disease : Asthma or COPD
What lung disease?
Low FEV1
Low FVC
FEV1<FVC
High FRC
Normal DLCO 📍
Asthma
What lung disease?
Low FEV1
Low FVC
FEV1<FVC
High FRC
Low DCLO 📍
COPD
What lung disease?
Low FEV1
Low FVC
FEV1>FVC📍
Low FRC 📍
Restrictive Lung Disease
Where is this formula used?
PO2 x Solubility of O2 in blood = _____________
Dissolved gases
What happens to the net diffusion of O2 when the partial pressures of O2 in alveolar air and pulmonary capillary are equal?
There is no more net diffusion of O2 ( Ficks Law)
Expected alveoli finding in an infant born prematurely with neonatal respiratory distress syndrome?
Collapse of the small alveoli
Surfactant appears between 24th and 35th gestational week. In the absence of surfactant , surface tension is too high , the small alveoli will collapse into larger alveoli.
Hypoxia causes vasoconstriction in this vascular bed?
Pulmonary
12/M cyanotic, had a severe asthmatic attack with arterial PO2 of 60mmHg and PCO2 of 30mmHg. What is the explanation for low PCO2?
His arterial PCO2 Is lower than normal because hypoxemia is causing him to hyperventilate.
12/M cyanotic, had a severe asthmatic attack with arterial PO2 of 60mmHg and PCO2 of 30mmHg. What is the drug classification of the treatment ?
B2 adrenergic agonist
Intrapleural pressure level during inspiration?
Intrapleural pressure is more negative than it is during expiration.
Volume that remains in the lungs after a tidal volume is expired?
Functional Residual Capacity
35/M with this following lung volumes, what’s the ERV?
VC: 5L
TV: 0.5 L
IC: 3.5 L
FRC: 2.5L
1.5 L
ERV= VC - IC
Blood flow in the lungs when a person is standing is highest where?
Highest at the base because that is where the difference between arterial and venous pressure is greatest.
What happens to the FRC during atmospheric pressure?
When an airway pressure is equal to the atmospheric pressure, it is designated as zero pressure.
- when the airway pressure is zero ( atmospheric) , the volume of the combined system is the functional residual capacity.
Site of highest airway resistance?
Medium sized bronchi
49/M with pulmonary embolism and with complete blocked blood flow to his left lung. Effect on alveolar PO2 of the left lung?
Alveolar PO2 in the left lung will be approximately equal to the PO2 in inspired air.
- this is because there is no blood flow to the left lung , and no gas exchange between the alveolar air and pulmonary capillary blood.
Strenuous exercises causes a shift from where ?
Shift from curve A to curve B
aka
Shift to the right; Increased unloading of O2, decreased affinity of O2
Effect on P50 when there’s a shift from curve A to curve B / shift to the right?
Increased P50
Volume remains in the lungs after a maximal expiration?
Residual volume
Resistance in the pulmonary circulation compared to systemic circulation?
Lower resistance
- blood flow or cardiac output is nearly equal. Pulmonary circulation is characterized as having both lower pressure and resistance.
65/M compute for the alveolar ventilation with the following values:
TV: 0.45L
RR: 16
Arterial PCO2 : 41
Expired PCO2: 35
6.14 L/ min
- Alveolar ventilation is the difference between tidal volume and dead space multiplied by breathing frequency.
- Dead space= 0.45 x (41-35/41) = 0.066L
- Alveolar ventilation = (0.45L- 0.066L) x 16bpm = 6.14 L/min
PCO2 at the base of the lungs compared with the apex ?
Higher pulmonary capillary PCO2