exam 1 class 7 Flashcards
As inhaled air becomes humidified passing down the airways,
what happens to the PO2 of the air?
the partial pressure of oxygen decreases (addition of water vapor dilutes the concentration of oxygen in the air mixture)
4 lung volumes
tidal volume
inspiratory reserve volume
expiratory reserve volume
residual volume
lung volumes vary considerably with?
age, sex, height, and weight
the volume of air that moves during a single inspiration or expiration ( breath quietly)
tidal volume
average tidal volume
500 mL
additional volume that you inspire above the tidal volume ( breathing in as much additional air as you can)
inspiratory reserve volume
amount of air forecefully exhaled after the end of a normal expiration ( pushing out as much air as possible)
expiratory reserve volume
expiratory reserve volume average
1100 mL
after you blow out as much air as you can the air left over that remains in your lungs still ( maximum exhalation what is left over still inside)
residual volume
T or F lung volumes differ between male and females
true
sum of two or more lung volumes is called?
lung capacity
Primary muscles involved in quiet breathing (breathing at rest) are:
diaphragm, external intercostals, and scalenes
Air flow in the respiratory tract obeys:
flow of change in pressure /resistance
delta P/R means
- air flows in response to a pressure gradient
- flow decreases as the resistance of the system to flow increases
inspiration occurs when?
alveolar pressure decreases
- at rest
- inspiration
- expiration
-at rest: diaphragm is relaxed
- inspiration: thoracic volume increases
- expiration: diaphragm relaxes thoracic volume decreases
what do external intercostal and scalene muscles do during inhalation
contract and pull the ribs upwards and out
inspiratory muscles
external intercostals and scalenes
brief pause between breaths, alveolear pressure is equal to atmospheric pressure ( when pressures are equal there is no air flow)
time 0
inspiration increase in the thoracic volume, alveolar pressure falls about 1 mm Hg below atmospheric pressure, and air goes into the alveoli
time 0-2
expiration occurs when?
alveolar pressure increases
expiration during quiet breathing does not require active muscle contraction
passive expiration
air pressure in the lungs increases and reaching maximum 1 mm Hg above atmospheric pressure, alveolar pressure is higher than atmospheric pressure
time 2-4 expiration
after expiration air movement stops when alveolar pressure is equal again to atmospheric pressure
time 4