Mechanics1

Question 1

transpulmonary pressure

Answer 1

=PA-Pip. pressure acting to inflate lungs.

Question 2

transthoracic pressure

Answer 2

=Pip-PB. pressure acting on thoracic wall

Question 3

Transrespiratory pressure

Answer 3

=PA-PB. potential pressure gradient for flow into or out of the alveoli w/ glottis closed

Question 4

hysteresis

Answer 4

the idea that lungs are more compliant on expiration than inspiration. Produced by surfactant.

Question 5

three functions of surfactant

Answer 5

1. reduce surface tension (causes surface tension to vary with surface area)
2. preserve alveolar integrity (prevent small from emptying into large)
3. prevents transudate (edema)

Question 6

what determines FRC?

Answer 6

balance b/w the force of lungs pulling in and chest wall pulling out

Question 7

How does decreasing lung compliance change FRC and Pip? Chest wall compliance?

Answer 7

You get smaller FRC and more neg PIp.

You get larger FRC and more neg Pip.