Lung Volumes Flashcards
How do you measure the volume of lungs?
Spirometer
What is Tidal Volume?
Air volume normally breathed
What is inspiratory reserve?
The additional amount you can inhale on demand
What is expiratory reserve?
The additional amount that you can exhale on demand
What is residual volume?
The amount of space that you will not be able to exhale
This is so that your alveoli dont collapse. .
What is vital capacity?
The volume that you can maximally inhale/exhale together
What is total lung capacity?
The vital capacity plus the reserve volume
When is there a balance of pressure during breathing?L
at the end of passive exhalation
Can you measure anything with residual in the title?
NO
How do the volumes change in restrictive diseases?
All the volumes decrease
Cant expand enough
Increased fibers in the interstitium
How do the volumes change in obstructive diseases?
All the volumes increase
Barrel shaped chest
Cant exhale, air is trapped
What is inspiratory capacity?
from passive exhalation to max inhalation
What are some helpful spirometric values?
Forced vital capacity
Forced expiratory volume in the first second
Ratio of FEV1 to FVC (percentage)
Forced expiratory flow in the middle of expiration
What is forced vital capacity?
FVC
total volume of air that can be forcibly expired after a maximal inspiration
What does the FEV1/FVC ratio tell you?
The resistance to flow. Small ratio is bad
How much of your air do you breath out in the first second?
80%, then it slowly declines
damage in the large airways will reflect in a change in what part of the flow-volume curve?
The rapid incline of expiration up to the peak
Damage in the small airways will reflect in a change in what part of the flow-volume curve?
The slower declined rate of expiration after the peak flow.
How will the flow-volume curve look for obstructive disease?
It will look like an upside down comma
Total lung capacity will be increased, Forced vital capacity will increase, Rate of increased flow will be steeper, decline will also be steep, then will flatline at a slow flow.
flow will never be as high on inspiration/exhalation
How will the flow-volume curve change in response to an upper airway obstruction?
The peak in flow on inspiration and exhalation will be cut off. plateaus in both.
How will the flow-volume curve change in response to a restrictive lung disease?
It will be identicle, but smaller and shifted to the right
What is normal FEV1/FVC value?
.8
What is the FEV1/FVC value in obstructive lung disease?
Less than .7.
Both FEV1 and FVC decreased
FEV1 decreased more
What is the FEV1/FVC value in restrictive lung disease?
greater than .8.
Both FEV1 and FVC are decreased but FVC is decreased more
What is the definition for physiological dead space (VD)
total volume of the lungs that does not participate in gas exchange
VD=Anatomical dead space+Functional dead space
What is anatomical dead space?
Volume of the conducting airways
VD=Anatomical dead space+functional dead space
What is functional dead space?
Alveoli that do not participate in gas exchange
What is Minute ventilation?
Total rate of air movement into and out of the lungs
Minute ventilation=Tidal Volume x Respiration rate
What is alveolar ventilation?
The rate at which new air reaches the gas exchange areas of the lungs
Alveolar ventilation=Respiration rate x (Tidal volume-dead space)
What does the alveolar ventilation equation describe?
It shows the Inverse relationship between alveolar ventilation and alveolar PCO2.
Alveolar ventilation=Rate of CO2 prod x constant/alveolar PCO2
What cannot be measured by spirometry?
Residual volume, forced residual volume, and Total lung capacity
