What is pulmonary ventilation?
Inspiration and expiration of air between atmosphere and lungs
What is EXTERNAL respiration?
What is internal respiration?
Exchange of gases that takes place at tissues
What is Boyles law?
When temp of GAS is constant, pressure of a gas varies INVERSELY, (as vol increases pressure decreases and viceversa)
Can you exaplain airflow exchange using the actual atmospheric pressures. (760mmHg ATM)
What is intrapleural pressure?
-What is its pressure in relation to atmosphere and intrapulmonary pressure
-How is it created?
What are the RESISTANCE forces to overcome for BREATHING?(4)
1)lungs compliance:
- Elastic recoil of the lungs during inspiration
- Mobility of the chest wall
- SURFACE tension
-2)Airways resistance
What is the formula to calculate COMPLIANCE ?
Change in pressure
A patient inhales 500 ml of air on a spirometer
intrapleural pressure before inspiartion was -5 cmH20, at the end of inspiration it was -8 cmh20,
What is the compliance?
change in vol in L = 0.5
Change in pressure = (-5–8)
0.5/3 = 0.1667 L/cm H20
What does the LAPLACE’S law describe?
it describes the relationship between Pressure, surface tension and alveolar radius
What is the formula for the relationship bw pressure, surface tension and alveolar radius?
P= 2T
—
r
What is SURFACTANT important in relation to LAPLACE’S law?
because it reduces TENSION (T in the part of the equation)
EQUALIZING pressure difference between small and large alveoli!
How does SURACTANT help maintain a uniform alveolar size?(4)
What is neonatal respiratory stress syndrome?
Air way resistance is mainly affected by what?
radius
Airways resistance is mainly affected by the radius, as radius decrease airway resistance increases.
Moving down the respiratory system, airway radius decreases significantly, however RESISTANCE decreases instead of increasing? Why is that?
As you move down respiratory path, the radius does decrease significantly, however the Quantity of pathways increases as it branches so resistance is low compared to the many millions amount of branches in the respiratory system.
What are the factors that can affect AIRWAY RESISTANCE?
What is FVC?
amount of air you can breath out after a max inhalation
What is FEV1?
What is FEV1 as percentage in relation to FVC?
70-80%
What does the PEAK FLOW METER measure?
it measures the SPEED at which you are able to breathe out
What can be used to measure lungs and volume capacities?
spirometer
What is tidal volume?
volume of air inhaled/exhaled in one quiet breath
What is ERV?