Respiratory Physiology

Question 1

4 basic lung volumes and the sums of each

Answer 1

Basic - Inspiratory Reserve Volume, Tidal Volume, Expiratory Reserve Volume, Residual Volume

Inspiratory Capacity = IRV + TV
Functional Residual Capacity = ERV + RV
Vital Capacity = IRV + TV + ERV
Total Lung Capacity = ALL

Question 2

Effect of air bubble in ABG sample PO2 and PCO2

Answer 2

PO2 increases, PCO2 decreases

Question 3

Effect of the ff on lung compliance
A. Pulmonary Edema
B. Low Surfactant (RDS)
C. Aging
D. Emohysema
E. Asthma (increase airway resistance)

Answer 3

A and B - decrease
C and D - increase
E - no effect

Question 4

What is a forced vital capacity

Answer 4

Inspire to total lung capacity then expire to residual volume
“Forcing patient to exhale his vital capacity”

Question 5

Obstructive lung disease have increased _____ (lung volume parameter

Answer 5

Residual volume and total lung capacity

IV EV are decreased

Question 6

Estimated volume of anatomic dead space

Answer 6

1mL/lb

Question 7

Variation of pulmonary vascular resistance with respect to lung volume

Answer 7

Lowest at FRC, increases at high and low lung volumes
High - alveolar air compression
Low - positive intrapleural pressure

Question 8

The glossopharngeal nerve is the afferent pathway for which regulation system of respiration

Answer 8

Carotid body chemoreceptors

Question 9

The vagus nerve is the afferent pathway of which receptors

Answer 9

Aortic chemoreceptors
J receptors
Irritant airway receptors
Stretch receptors in hering breur reflex

Question 10

Which airways have more turbulent airflow? Central or peripheral

Answer 10

Central

Faster flow means higher turbulence

Question 11

Pulmonary wedge pressure estimates the pressure in which heart chamber?

Answer 11

Left atrium

Question 12

How does hypoxia promote increased pulmonary blood flow?

Answer 12

Adjacent pulmonary vessels vasoconstrict, increasing resistance, which makes blood pass though well aerated areas instead.

Avoids VQ mismatch

Question 13

Pulmonary blood pressure is higher in upper or lower lung fields?

Answer 13

Lower

Question 14

3 zones of lung flow and example

Answer 14

Zone 1 - no flow throughout cycle - pathologic if too high alveolar pressure or too low capillary pressure
Zone 2 - intermittent flow - apices at rest
Zone 3 - continous flow - rest of lung, or during exercise

Question 15

How does lung accomodate to increased blood flow during exercise

Answer 15

Increase open capillaries and distending them. Pulmonary vessels are compliant

Question 16

What keeps negative pressure in the pleura

Answer 16

Lymphatic drainage

Question 17

Which diffuses faster O2 or CO2

Answer 17

CO2. Lower pressure gradiebt is required for diffusion