Respiration 2 Flashcards
Dalton’s Law
each gas contribute to total pressue
Henry’s law
at a given temp, the amount of a particular gas is directly proportional to the partial pressure of the gas
fick’s law
diffusion of gas depends on the molecular weight and solubility of the gas, the surface area and the thickness of the membrane
total atmospheric pressure:
760 mmHg (Dalton)
Nitrogen accounts for:
78.6% or 597mmHg(Dalton)
Oxygen accounts for:
20.9% of air or 159mmHg(Dalton)
CO2 accounts for:
0.5% of air, or 3.8 mmHg(Dalton)
Each gas will dissolve in liquid in proportion to:
it’s partial pressure (Henry)
at equilibrium, the partial of the two phases (gas, liquid) will be:
equal
amount of each gas that will dissolve into liquid depends on:
solubility (CO2 is 20x more soluble in water than O2), little N2 will dissolve; and temperature (temp increases, solubility decreases) (henry’s law)
issues that effect gas diffusion at respiratory membrane:
The differences in partial pressure across the respiratory membrane are substantial. The distances involved in gas exchange are small. The gases are lipid soluble. The molecular weight of the gases is small. The total surface area is large. Blood flow and airflow are coordinated. (e.g. Blood flow is the greatest around alveoli with the highest PO2, where O2 uptake can proceed with maximum efficiency).
The differences in partial pressure across the respiratory membrane:
substantial
The distances involved in gas exchange are
small
the gases are:
lipid soluble
molecular weight of the gases is:
small
total surface area of gases is:
large
bloodflow and air flow are coordinated becasue:
blood flow is greatest around alveoli where the PO2 is the highest
alveolar gas carries _____ CO2 than atmospheric air:
much more
atmospheric gas PO2/Alveolar gas
159/100
atmospheric gas PCO2/Alveolar gas
3.8/40
before pulmonary capillaries exchange gas, the ratio of O2/CO2 is;
40/45
After the pulmonary capillaries exchange gas, the ratio of O2/CO2 is:
100/40 (same as in the Alveolus)
CO2 is _____ times more soluble in the plasma and alveoli fuild than O2
20x
ratio of O2/CO2 in systemic capillaries before exchange with the tissue
O2=95, CO2=40.
ratio of O2/CO2 in systemic capillaries after exchange with the tissue
O2=40,CO2=45
levels of PO2 at atmospher, alveolar, tissue:
159,100,40
Level of PCO2 at atmospher, alveolar, and tissue:
3.8, 40,45
•O2 is carried in blood in two ways:
o1. 5% is dissolved in plasma
o98. 5% is bound to each Fe of hemoglobin (Hb) in RBCs
Each Hb molecule is composed of four:
polypeptide chains (2a and 2b subunits), each with an iron-containing heme group