L2+3 Static and dynamicMechanics

Question 1

What will determine lung compliance?

Answer 1

1. Elastic fibers and collagen in the lungs

2. Surface tension forces ( produced due to the presence of alveolar-liquid surface )

Question 2

What are the pathologic conditions and what are there compliance ?

Answer 2

• fibrosis ( low compliance)

- emphysema ( high compliance )

Question 3

What is the total pressure difference to inflate the lungs ?

Answer 3

1. Pressure to overcome lung compliance
2. Pressure to overcome dynamic resistance
   A- airway resistance (80%)
   B- viscous tissue resistance (20%)

Question 4

What are the factors that determine the airway resistance ?

Answer 4

1. Volume of the lung
2. Bronchial smooth muscle tone
3. Airways diameter
4. Density and viscosity of inspired air

Question 5

What is the mean dynamic compliance in the graph ?

Answer 5

the slope of the line that joins the end-inspiratory and end-expiratory points of no flow.

Question 6

What is the relation between the breathing rate and resistance in normal individuals ?

Answer 6

In normal people:

- slow breathing —

Question 7

What does the total work of breathing depends on ?

Answer 7

1. Elastic forces

2. Airway resistance