gas exchange and acid base regulation Flashcards
this law states that the rate of gas transfer (V gas) is proportional to the tissue area, the diffusion coefficient of the gas and the difference in the partial pressure of the gas on the two sides of the tissue and is inversely proportional to the thickness
ricks law of diffusion
partial pressure can be determined by
the specific % of fractional content of the gas in the gas mixture x the absolute barometric pressure
the total pressure is equal to the sum of the arptial pressures of the gases is known as
Dalton’s law
air is composed of
oxygen, carbon diode and nitrogen
calculation of partial pressure
Pair = PO2 + PCO2 + PN2
T or F: when we say there is less oxygen at higher altitudes, what we really mean is that the air is less dense
true - the percentage of each gas is the same but the concentration of the gases is less
what happens if another gas was added to the atmosphere?
the absolute barometric pressure would not change - the partial pressure of each gas would decrease but the absolute barometric pressure would not change
The rate of gas transfer (V gas) is proportional to the tissue area, the diffusion coefficient of the gas, and the difference in the partial pressure of the gas on the two sides of the tissue, and inversely proportional to the thickness.
ricks law of diffusion
v gas =
rate of diffusion
v gas =
A/T x D x (change of P)
a ]
tissue area
T =
tissue thickness
D=
diffusion coefficient of gas
P1 - P2 =
difference in partial pressure
the rate of diffusion of O2 and CO2 is proportional to the
pressure gradient, surface area
diffusion constant relationship is inversely proportional to the
thickness of the membrane
the diffusion constant is influenced by the
solubility of the gas
the greater the solubility of a gas, what happens to the pressure gradient?
the lower the pressure gradient needed for the gas to diffuse across a membrane
T or F: the membrane solubility of CO2 is 20x greater than O2
true
T or F: the pressure gradient needed for CO2 is much less than the pressure gradient needed for O2 to diffuse across the respiratory membrane
true
blood flow to the lungs is described in terms of
zones
zone 1
capillary pressure < alveolar pressure
zone 2
capillary pressure is intermittently > alveolar pressure
zone 3
capillary pressures is > alveolar pressure
pressure in the capillaries is affected by
hydrostatic pressure
pulmonary circuit
-same rate of flow as systemic circuit
-lower pressure
ventilation/perfusion ration (V/Q)
-indicates matching of blood flow to ventilation
- ideal = 1.0 or above if blood flow is high
apex of lung (standing at rest)
- under perfused (V/Q ratio >1.0)
base of lung (standing rest)
- overperfused (V/Q ration < 1)
-gravitational force - zone 3
during upright exercise, blood flow will?
increase to top of lung (apex)
light to moderate exercise will _____ V/Q ration
improve
exercise converts all areas of the lungs to zone
zone 3 perfusion
heavy exercise may result in V/q
inequality
each gram of hemoblgobbin binds to
four 4 molelecues of oxygen
what happens to O2 transport in the blood
- bounds to hemoglobin >98% of total
- dissolved in the blood. < 2% of total
binds how many O2 molecule per heme group
1