Term
|
Definition
| total number of gas molecules per volume unit |
|
|
Term
| What is partial pressure? |
|
Definition
| total pressure X the % of the gas in question |
|
|
Term
True or False
Inspired air is 100% saturated with water when it reaches the respiratory zone |
|
Definition
|
|
Term
| What affects diffusion of gases in the alveoli? |
|
Definition
alveoli & blood partial pressures
ventilation of alveoli
tissue consumption |
|
|
Term
True or False
Changes in atmospheric pressure does not have a significant effect on CO2 diffusion |
|
Definition
|
|
Term
| Blood entering the alveolar capillaries has (low/high) pO2 |
|
Definition
|
|
Term
| What determines the exchange of gases between the alveoli & capillaries? |
|
Definition
-partial pressure gradients
-surface area available for diffusion
-thickness of air-blood barrier
-physical properties of the gas |
|
|
Term
True or False
Humans at rest will have an optimum level of blood flow vs ventilation to maximize gas exchange |
|
Definition
| False, gravity means that less blood is flowing to the top of the lung, perfusion is less than ideal |
|
|
Term
| What is hypoxic vasoconstriction? |
|
Definition
| constriction of blood vessels when alveoli are poorly ventilated, directing blood instead to the more well ventilated alveoli |
|
|
Term
| What initiates hypoxic vasoconstriction? |
|
Definition
| a reduction of pO2 or increase in pCO2 in interstitial fluid |
|
|
Term
| What effect does a thickening of the alveolar-capillary membrane have on gas exchange? |
|
Definition
| -decreases rate of diffusion |
|
|
Term
| What effect does a high altitude or low pO2 in the atmosphere have on gas exchange? |
|
Definition
| -decreases the oxygen pressure in alveoli, decreasing the driving pressure |
|
|
Term
|
Definition
| inadequate ventilation of the lung |
|
|
Term
| What is ventilated-perfusion inequality? |
|
Definition
| a ventilated alveoli with no blood supply, or vice-versa |
|
|
