Lung Volumes and Lung Capacities
What does functional residual capacity equal?
FRC = RV + ERV
How many volume subdivisions are there?
Four
This is known as one of the most stable points to major in a patient?
Functional residual capacity - Often used as a reference volume by physicians
Ventilation in the areas of anatomic dead space results in no ___ ?
Gas exchange
What does inspiratory capacity equal?
IC = TV + IRV
What is the hallmark of finding obstructive disease?
Increase in ratio of residual volume to TLC
What is chronic bronchitis?
Increase in secretion of airways
In obstructive disease, what happens to the ratio of RV to TLC?
Increases
What is a lung capacity?
Involves 2 or more of the individual lung volumes
What can cause difficult in breathing due to chestwall deformities?
Irregular bending of spine
Vital capacity is the ___ volume that can be measured with a spirometer?
Largest volume
How much clinical significant does inspiratory capacity have?
Little clinical significance
What is the only volume which cannot be measured with a spirometer?
Residual volume
You cannot measure any capacity that has what component in it?
Residual volume
This is defined clinically as a decreased TLC?
Restrictive disease - Difficulty getting air in
What is fibrosis?
Scarring of lung
What will decrease in restrictive disease (3)?
TLC, RV, FRC
What will increase in obstructive disease (3)?
TLC, RV, FRC
Minute ventilation can be described as the air?
That moves past your lips
What is the tidal volume (TV)?
The amount or gas inspired or expired with each breath
What is minute ventilation?
The flow moved into or out of the lungs (Volume/ time)
What is the inspiratory reserve volume (IRV)?
The max amount of additional air that can be inspired from the end of a normal inspiration
What is the expiratory reserve volume (ERV)?
The max volume of additional air that can be expired from the end of a normal expiration
What is vital capacity (VC)?
The maximum volume of air that can be forcefully expelled from the lungs following a maximal inspiration
What is the inspiratory capacity (IC)?
The maximum volume of air that can be inspired from end expiratory position
What is the total lung capacity (TLC)?
The volume of air contained in the lungs at the end of a maximal inspiration
What is the residual volume (RV)?
The volume of air remaining in the lung after a maximal expiration
What is the functional residual capacity (FRC)?
The volume of air remaining in the lung at the end of a normal expiration
What is sarcoidosis?
Tumor like growths that make lungs stiffer
In obstructive disease, what will decrease?
VC
In restrictive disease, what will decrease?
VC
What does vital capacity equal?
VC = TLC - RV
What will occur to the ratio of RV/ TLC in restrictive disease?
Will decrease or stay the same
If you go to residual volume, what fraction of TLC is still left in your lungs?
~25%
What is the normal % of FRC?
50%
On avg, what is the tidal volume in/out?
500mL
What is the normal value of minute ventilation?
7.5 L/ min
What is the normal % of RV?
25%
What are the three features of the volume subdivisions?
1) Do not overlap 2) Can not be further divided 3) When added = total lung capacity
What two diseases make up COPD?
1) Emphysema 2) Chronic bronchitis
What are the three major obstructive diseases?
1) Emphysema 2) Chronic bronchitis 3) Asthma
What are four examples of restrictive diseases?
1) Fibrosis 2) Sarcoidosis 3) Muscular weakness diseases 4) Chestwall deformities
What are some areas of anatomic dead space?
1) Mouth 2) Pharynx 3) Larynx 4) Trachea 5) Bronchi
What three volumes/ capacities can you NOT use a spirometer to measure?
1) TLC 2) FRC 3) RV
What are the four basic lung volumes?
1) Tidal volume (TV) 2) Inspiratory Reserve Volume (IRV) 3) Expiratory Reserve Volume (ERV) 4) Residual Volume (RV)
What are the four basic lung capacities?
1) Total lung capacity (TLC) 2) Vital capacity (VC) 3) Functional residual capacity (FRC) 4) Inspiratory capacity
What is the total lung capacity the sum of?
All four basic lung volumes
What is emphysema?
Alveoli are broken down, air spaces are larger reducing surface area
The volume of the lung not involved in gas exchange is known as?
Anatomic dead space
How do you measure minute ventilation?
Collect expired volume for a fixed time
How are restrictive diseases clinically identified?
Decrease in TLC
What is a restrictive disease?
Difficult to get air into lungs
What is an obstructive disease?
Difficult to get air out of the lungs
Obstructive disease is ___ as restrictive disease is ___ ?
Disproportionate, Proportionate
