Week 10: Oxygenation Flashcards
(67 cards)
What is pressure?
Force exerted on surfaces gas molecules are in contact with
What is partial pressure?
Pressure of single type of gas in a mixture
What is Total Pressure?
Sum of all partial pressures of gaseous mixture
What is Dalton’s Law?
Total pressure exerted by a mixture of gases is the sum of the partial pressures of the gases in a mixture
What is Henry’s Law?
Concentration of gas in a liquid is directly proportional to the solubility and Px of the gas
What is the relative concentration of gases?
Nitrogen > Oxygen > Water Vapour > Carbon Dioxide
Is the amount of water vapour greater in the alveolar air or in the atmospheric air?
Alveolar air
What is Ventilation?
Movement of air into and out of the lungs
What is Perfusion?
Flow of blood in pulmonary capillaries
For gas exchange to be efficient, volumes involved in Ventilation/Perfusion should be …..
Compatible
Factors that can lead to ventilation/perfusion imbalance:
- Regional gravity effects on blood
- Blocked alveolar ducts
- Disease
What is the Px of O2 in alveolar air?
104mmHg
Sufficient Ventilation means that O2 enters alveoli at high rate, Px remains high, which means what?
Adequate gas exchange occurs
Poor Ventilation means that Px of O2 in alveoli drops, which means what?
Inadequate gas exchange occurs
What is a Compensatory mechanism for Ventilation and Perfusion?
Body will redirect blood flow (constriction of pulmonary arterioles) to alveoli that are receiving sufficient ventilation; pulmonary arterioles at these sites will vasodilate increasing blood flow
Ventilation is regulated by…
The diameter of the airways
How does the diameter of the airways impact Ventilation?
A greater Px of CO2 in alveoli and decrease level of O2 in alveolar blood supply cause bronchioles to dilate, causing CO2 to be exhaled at greater rate
Perfusion is regulated by…
The diameter of blood vessels
How does the diameter of the blood vessels impact Perfusion?
Greater Px of O2 in alveoli cause pulmonary arterioles to dilate, increasing blood flow
What are the 2 sites where Gas Exchange occurs?
The lungs and the tissues
Where in Gas Exchange is O2 picked up and CO2 is released at the respiratory membrane?
The Lungs
Where in Gas Exchange is O2 released and CO2 is picked up?
The Tissues
What is External Respiration?
Exchange of gases with EXTERNAL environment (alveoli of lungs)
What is Internal Respiration?
Exchange of gases with INTERNAL environment (tissues)