F - Mechanics of Breathing - Ballam

Question 1

Compliance

Answer 1

Greater compliance means it is more easily stretched

Inversely related to stiffness or elastance

Question 2

Emphysema

Answer 2

High compliance
Do not recoil as forcefully when tension released at end of inspiration so less air leaves
Increased residual volume
FEV1 and FEV1/FVC is less - airways tend to collapse during forced expiration

Question 3

Pulmonary fibrosis

Answer 3

Lower compliance - doesn’t easily stretch
Elastic recoil is greater - air leaves quickly
FEV1/FVC is greater than normal

Question 4

What is the greatest contributor to the elastance of the lungs?

Answer 4

Surface tension

Question 5

Surfactant

Answer 5

Disrupts and reduces surface tension
Increases compliance - easier to stretch
Neonatal respiratory distress syndrome when missing from infants

Question 6

Flow

Answer 6

(Q)
Change in pressure divided by resistance
-as lungs expand they pull open airways and reduce resistance

Question 7

Vigorous ventilation

Answer 7

Pressure, flow and volume changes are accentuated

-accessory m. are recruited

Question 8

Obstructive lung diseases

Answer 8

Asthma, COPD
Decreased FEV1/FVC
Increased resistance to flow

Question 9

Restrictive lung diseases

Answer 9

Fibrosis
Reduced compliance
Increased FEV1/FVC