Lecture 6: Respiratory System pt. 2 Flashcards
What contributes to make up Barometric Pressure?
Partial pressure of oxygen, carbon dioxide, nitrogen
What do you treat the partial pressure as?
A concentration
PO2 is always ______% of barometric pressure
21%
Why is it 21%?
Because in naturally occurring air on earth, oxygen is ALWAYS 21% of the air.
In high elevation, why is there the same proportion of oxygen all around?
Because theres the same proportion of oxygen and barometric pressure is lower. ( same percentage of oxygen but it is 21% of a LOWER number of a “big easy”???)
6:03
When we change barometric pressure, what does it change?
What the PO2, PCO2, Nitrogen is
The closer you are to the surface of the earth at sea level,….
the more stronger gravity can pull on it and the higher the pressure you have.
As altitude goes up, what happens?
Barometric Pressure goes down
For instance, if you were at a place where Barometric was 700, what would be the PO2 in that area?
The PO2 would 21% of 700. It would be 140.
For instance, if you were at a place where Barometric pressure was 300, what would the PO2 be in that area?
The PO2 would be 21% of 300. It will be 60
The bigger the concentration gradient is,
the more will move from point A (high) to point B ( low).
As the PO2 drops when going up in altitude,
the gradient gets smaller so less oxygen gets movin from the alveoli into the blood
What is a pulmonary capacity?
A pulmonary capacity is something we can measure. (two or more volumes added together)
What are the Pulmonary Volumes?
Tidal Volume, Expiratory Reserve Volume, Inspiratory Reserve Volume, Residual Volume
What is a Tidal Volume?
Volume of air in a normal expiration after a normal inspiration
What is the normal Tidal Volume?
About 500 ml of air
What is Expiratory Reserve Volume?
Amount of air you can breathe out AFTER you breathe out tidal volume
What is the normal ERV?
About 1.0 - 1.2 L of air
What is Inspiratory Reserve Volume?
The volume of air you can inspire forcibly after a normal inspiration.
What is the normal IRV?
About 3.3 L of air
What is Residual Volume?
The volume of air you cannot force out of your lungs
What is the normal RV?
About 1.2 L of air
Why is IRV bigger ERV?
It leaves us room at the top so if we need to have deeper breaths bc we’re exercising more, we have a lot of room above TV to do that.
What are pulmonary capacities calculated by?
By adding together pulmonary volumes
What is Total Lung Capacity?
The maximum amount of air you have in your lungs.
About 6 L of air.
What is the equation for Total Lung Capacity?
RV + ERV + TV + IRV
What is Vital Capacity?
The maximum amount of air you can move in and out of your lungs
How can you calculate Vital Capacity?
- Total lung capacity - Residual Volume
OR - IRV + TV + ERV
Why do we care about VC?
As residual volume goes up, VC goes down. The amount of air you move in and out of your lungs, decreases as RV goes up.
What can affect Vital Capacity?
The size of a person (smaller person has a lower VC than a taller person)
If there is more blood volume, what happens?
Less room for air
If you have excessive fluid in either abdominal cavity or pleural cavity, VC goes down. Why?
In the abdominal cavity, excessive fluid can keep diaphragm from moving down as much as it would like to and not so much of a pressure change.
If there is excessive fluid in the pleural cavity, the pleural fluid CAN’T BE COMPRESSED making the lungs be compressed.
What happens in Emphysema?
Alveoli gets stretches out and doesn’t have elastic recoil.
When someone with Emphysema breathes out, what happens?
less air leaves. RV is higher.
You can’t get more air out.
What are the hints to how somebody has emphysema?
Someone w/ emphysema has to work to breathe out. Very well developed neck muscles: to use to breathe out. Barrel chested: more air left in lungs after a normal respiration
What is Inspiratory Capacity?
The amount of air you can breathe in AFTER a normal expiration