3: Pulmonary Physiology

Question 1

How thick is the parietal space containing parietal fluid?

Answer 1

5-25 um thick

Question 2

Why do we use cm H2O instead of mmHg

Answer 2

Because the pressures of respiratory physiology are relatively small

Question 3

FRC represents an equilibrium between what two forces in the lungs?

Answer 3

Elastic recoil + tendency for the chest wall to spring forward

Question 4

Emphysema vs fibrosis: compliance and elastic recoil

Answer 4

Emphysema: high compliance, low recoil
Fibrosis: low compliance, high recoil

Question 5

Hysteresis

Answer 5

Inflate the lungs with saline -> compliance is very high

Question 6

LaPlace’s law

Answer 6

Surfactant reduces tension in the smallest alveoli more than in larger alveoli

Question 7

What are the breaths like of a person with fibrosis?

Answer 7

More shallow volume, more frequently

Question 8

What happens to compliance and elasticity with age?

Answer 8

Compliance increases, elasticity decreases

Question 9

Airway resistance decreases how much with a one fold increase in diameter + equation

Answer 9

Decreases four fold (R = 8nL / r^4)

Question 10

Major therapeutic receptor target for asthma

Answer 10

B2-adrenergic receptors

Question 11

Interdependence in losing alveoli

Answer 11

When some alveoli are lost, this cause a loss of forces that normally counter collapse of the other alveoli, as alveoli help hold each other open