exam 3 lecture quizzes Flashcards
The posterior wall of the trachea is attached to the anterior wall of the….
esophagus
——- ——— couples the lungs to the thorax so they move as one unit.
Pleural pressure
During inspiration, alveolar pressure is… (+/-)
negative
as the pressure differential increases, the airflow…..
increases
(Airflow is proportional to pressure differential)
which muscle changes the superior-inferior dimensions of the lung-thorax unit when it contracts?
diaphragm
are the internal intercostals for expiration or inspiration?
expiration
which of the following muscles is the most superficial?
- External oblique
- Internal oblique
- Transverse abdominus
external oblique
Patient A has a vital capacity of 4 liters, a tidal volume of 0.5 liters, expiratory reserve volume of 1.5 liters, and residual volume of 1 liter. What is this person’s inspiratory reserve volume?
2 liters
(VC-TV-ERV=IRV … 4 - 0.5 - 1.5 = 2)
Patient A has a vital capacity of 4 liters, a tidal volume of 0.5 liters, expiratory reserve volume of 1.5 liters, and residual volume of 1 liter. What is patient A’s functional residual capacity?
2.5 liters
(ERV + RV = FRC … 1.5 + 1 = 2.5)
At 50% VC, recoil pressures are
positive
At 10% VC, recoil pressures are
highly negative
At rest, recoil pressure is
0
Below EEL, recoil pressure is
negative
What happens to lung dimensions when inspiratory muscles contract?
lung dimensions increase
where does air flow when inspiratory muscles contract?
into the lungs
when does air stop flowing into the lungs when inspiratory muscles contract?
when Palv=Patmos (alveolar pressure equals atmospheric pressure)
when inspiratory muscles contract, recoil pressure is….
positive
why is recoil pressure POSITIVE when inspiratory muscles contract?
stretching the lung-thorax unit results in a compressing force because it wants to collapse back to rest. compressing forces are positive so the recoil pressure is positive
to determine muscular pressure for expiration at a given volume, Pm(e)=
Pm(e)= Pe-Pr
to determine muscular pressure for inspiration at a given lung volume, Pm(i)=
Pm(i)= Pi-Pr
calculate the inspiratory muscular pressure from the following values:
Pi = -102
Pr = 16
-118
