Pulmonary Lecture 3 Flashcards
What occurs to the residual volume in Pulmonary Fibrosis?
It Decreases
What occurs to the functional residual capacity in Pulmonary Fibrosis
It Decreases
What occurs to the total lung capacity in Pulmonary Fibrosis
It Decreases
What occurs to the Vital Capacity in Pulmonary Fibrosis
It Decreases
What occurs to the FEV/FVC in Pulmonary Fibrosis
Small/No Change
What occurs to the lung in pulmonary fibrosis
The force of the lung deflates towards its intrinsic equilibrium position more quickly due to the increased rigidity
What is the relative size of the lung in pulmonary fibrosis
The lung is generally in a smaller state
What occurs to the residual volume in Bronchitis
It increases
What occurs to the functional residual capacity in Bronchitis
It Increases
What occurs to the total lung capacity in Bronchitis
There is no change - Bronchitis only changes airflow rate but not the size of the lung (capacity will remain unchanged)
What occurs to the Vital Capacity in Bronchitis
It Goes Down - This is because the TLC is unchanged and the RV goes up
What occurs to the FEV/FVC in Bronchitis
It decreases
What are the 2 Mechanical factors that effect Airway Resistance
- Mucous 2. Lung Volume
How does Lung Volume Effect Resistance
An increase in lung volume decreases resistance. As you inhale you pull apart the alveoli decreasing resistance. In obstructive diseases (bronchitis) those tend to breath at a higher lung volume to open their airways
Why does the Flow-Volume Curve drastically decrease due to Emphysema
The airways have a higher propensity to collapse during forced expiration.
How do the forced expiratory muscles respond to emphysema
They are used in quiet breathing causing the chest wall to exert force and causes a positive intrapleural pressure thus collapsing the airway
How is the use of expiratory muscles in exercise different than emphysema
There is not airway collapse due to the airway pressure. deep breath during exercise increases the airway pressure so no collapse occurs
What is the path for oxygen movement from inhalation
Airway–>Alveoli–>Diffuse into Pulmonary Capillary–>Heart–>lungs–>Arterial circulation
What is the desired partial pressure of oxygen in arteries under normal conditions
90-100 Torr at sea level 80-90 at Altitude
What is the definition of the partial pressure of oxygen
The force exerted on the walls of the arterioles by the oxygen molecules
What is the state of oxygen in the arterioles?
It is in a dissolved state (no longer gaseous)
What is the equation for the partial pressure of inspired air?
P=(PbXFo2) Pressure = Barometric pressure X Fraction of oxygen Must include Water: P= (Barometric Pressure - Water Pressure) x Oxygen Fraction P = (Barometric Pressure - 47 Torr) X 21%
What is the barometric Pressure and Oxygen Partial Pressure at Sea Lever
760 Torr and 150 Torr Respectively
Why is the Alveolar Oxygen Pressure less than the Inspired Air Pressure?
The difference of 150 to 100 has to do with CO2. The CO2 pressure offsets the Oxygen Pressure to 100.
What is the equation for Pressure of Alveolar Oxygen
PAO2=PIO2- (PACO2/R)
R=Respiratory Exchange Ratio = CO2 produced/O2 consumed
R=.8
P=150-(40/.8) = 100 Torr
What is the ideal CO2 Arterial Pressure?
40 Torr
Why does the body need to keep a residual CO2 balance in the blood
CO2 plays an important role in maintaining pH balance
(T/F) diffusion of Carbon Dioxide into the lungs is a fast process
True
What is the rate limiting step of Carbon Dioxide removal?
Ventilation - Air flow of Carbon Dioxide leaving the alveolus to the outside air. Slow Step
What occurs to Carbon Dioxide if you have a low ventilation rate?
Carbon Dioxide backs up in the blood because it cannot leave the alveolus quickly enough
Define Ventilation
Airflow in the lung
What is Minute Ventilation?
Volume of airflow through the lung in one minute (~6L)
What is alveolar ventilation?
Volume of Air flow in alveolar space in 1 minute (4.2 L)
What is the equation for Alveolar ventilation?
PaCO2= (VCO2/VA) x k
what will occur to the Pressure if Va decreases by 50%?
it will double
What happens to the PAO2 if the VA decreases
Combine Alveolar Ventilation Equation and Alveolar Gas equation:
The PACO2 will double thus:
Original: PAO2=PIO2-(PACO2/R)
Original: P=150 - (40/.8) = 100
Once Doubled: P=150-(80/.8) = 50
(T/F) Blood CO2 Is Directly Regulated by Alveolar Ventilation
True
(T/F) Blood O2 Is indirectly regulated by alveolar ventilation, via effects on Alveolar CO2
True
Define Hypoventilation
Low Ventilation
High Alveolar Ventilation and PCO2
Severe Obstructive Disease
Define Hyperventilation
High Ventilation
Low VA and PCO2
Caused by High Altitude
Define Hyperpnia
High Ventilation
Normal VA and PCO2
Exercise
