Diffusion of Pulmonary Gases and Gas Laws Flashcards
What is partial pressure?
- The pressure the gas exerts on the atmosphere. The gradient determines the movement across the membrane.
- The pressure of a specific gas in a mixture
- The total pressure of the mixture is calculated by adding all the pressures
- Partial pressure has strong effect on solubility. It forces gas into/out of solution. As partial pressure increases so does solubility.
- Less air friction at higher altitudes cause of pp is less.
Laws that govern passive diffusion?
- Dalton’s law
- Henry’s law
Each gas in a mixture of gases exerts its own pressure as if no other gases were present. Partial pressure is less at higher altitudes, percents are the same.
(see slide). what law?
Daltons law
O2 must dissolve in the _______
Plasma of the pulmonary capillaries before it can diffuse into the Hgb inside RBC
Quantity of gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility. (have to have both higher pp and solubility not just one) nitrogen doesn’t dissolve easily despite having high pp. Volume of gas that dissolves in a liquid determined by this law. What law is this?
Henry’s law
What is like dissolves like?
Molecules typically are most soluble in solvents with similar polarity.
_____ is 24 times more soluble than O2 in blood plasma.
CO2. is highly soluble, easier to de-air heart. CO2 helps get rid of O2 and N in heart. Example of soda bottle: increasing pp of co2 drives it into solution and releasing pp it comes out of the solution. CO2 dissolves in water easier than o2 and n2 cause its more polar.
How fast something will diffuse. The heavier the gas, the slower the rate of transfer. O2 is lighter than co2 so O2 has higher rate of diffusion. Can move faster across the membrane. Rate of diffusion of a gas through a liquid is directly proportional to solubility coefficient and indirectly proportional to square root of gram molecular weight. What law?
Graham’s law
Rate of gas transfer across a sheet of tissue is directly proportional to surface area of tissue. This means in terms of pp of gases the greater the differences of pp between 2 gasses the higher the gas transfer rate.
Fick’s law
The exchange of o2 and co2 between the alveolar air & pulmonary blood occurs in ________
Passive diffusion
78.6% nitrogen, move two spaces left.
.786 x 760mmhg=597.4mmhg
(calc example of daltons law)
Nitrogen has highest partial pressure in atmosphere
____ must dissolve in plasma of the pulmonary capillaries before it can diffuse into the hgb inside rbcs. Must do this before passing through the alvioli and binding to hemoglobin.
O2
Greater the surface area the _____ the gas transfer rate
Higher (ficks law)-Directly proportional
The thinner the membrane the _____ it diffuses
Quicker.(ficks law). Inversely proportional.
The higher the molecular weight of gas the _____ the gas transfer rate.
lower. ficks law. inversely proportional.
Gas transfer is ______ when pp is higher. Faster the transfer.
Higher. ficks law. Directly proportional.
ARD’s?
Lungs full of fluid, meaning less surface area for gas transfer.
v1/t1=v2/t2 is what? In the winter when pressure in something decreases it was related to the temp decreasing like tire pressure.
Charles law
Couple ways to drop metabolic demand?
*Lower temp (hypothermia)(left shift)
*Sedation
These allow body to function at basal metabolic rate that way we can meet metabolic needs w/ less equipment than body is capable of.
The more _______ you are the higher chance for edema
Hemodilated
Diffusion will happen ___________________ until both sides are the same O2 goes in or out and CO2 goes in or out.
In one direction or the other
Due to ______ you will still have Co2 in alvioli
Dead spaces
Atrial blood is ______
Venous blood is______
- Atrial-Oxygenated
* Venous-Deoxygenated
Transit time of blood in capillaries?
.75 seconds (see diagram)-same for co2
How long to fully saturate hemoglobin molecule with O2?
.25 seconds(see diagram)-same for co2
Hemoglobin carries ___ and ___. Each molecule capable of binding to one molecule.
O2 and Co2
1.5% of inhaled o2 dissolved in plasma.
98.5% bound to hemoglobin. (oxy-hemoglobin)
Each hemoglobin can bind a max of 4 O2
_____ is the most important factor that determines how much o2 binds to hgb.
pO2
High affinity means o2 bound tighter to hemoglobin what shift is this? p50 moves left pp gives lower saturation. This shift is increase in affinity.
Left shift.
O2 hemoglobin dissociation curve has _______ binding.
Non linear
_______ of o2 is the most important factor that determines how much o2 gets bonded to hemoglobin
Partial pressure. Pp dictates this binding.
p50 is normally ____mmHg
27mmHg
Decrease (low) affinity o2 are bound looser to hemoglobin. Lower affinity means it releases o2 to tissues easier we want affinity lower. what shift is this?
Right shift
DPG helps control _____. When higher amounts it decreases ______.
Affinity
What is the bohr effect?
The effect of pco2 and ph on the oxyhemoglobin curve.
3 main forms CO2 is transported?
- Dissolved co2 in blood plasma (7%)
- Carbamino compounds (23%)mostly bound to hgb. (haldane effect)
- Bicarbonate ions (70%)
What is the Haldane effect?
Lower oxyhemoglobin/higher co2 carrying capacity. Once hemoglobin gets to tissue and releases all that o2 now you have increase in binding sites which are no longer oxyhemoglobin lower oxyhemoglobin the higher the co2 carrying capacity that rbc now has so now co2 binds to brc much easier.
Cooling gas ______ solubility. Inverse relationship (temp and gas solubility.)
Increases
Hypothermia _____ co2 production
decreases
In hypothermia there is _____ affinity of hemoglobin with o2.
Increased. less o2 released to tissues. Left shift of oxygen-hemoglobin dissociation curve.
What are the 3 areas in the respiratory center?
- Medullary rhythmicity area(control basic rhythm of respiration)
- Pneumotaxic area (more rapid breathing rate, involuntary)
- Apneustic area (slower breathing rate, involuntary)
Important to know that when pnemotaxic are is ______ the apneustic area is _____ and vis a versa.
Stimulated, Inhibited.
Respiration is both voluntary and involuntary
Certain chemical stimuli alter how quickly and/or deeply we breath. Name 2 peripheral chemoreceptors
- Aortic bodies
* Carotoid bodies
Blowing off too much co2 can ______ the brain
Vasoconstrict
Hypoventilation
Hypercapnia/hypercarbia-abnormally elevated CO2 in blood.
Hyperventilation
Hypocapnia (hypocarbia)- rapid and deep breathing. Reduced CO2 in blood
By moving joints muscles you can activate
Proprioceptor stimulation of respiration
Temp goes up so does ______
Rate and depth
Pain, if something hurts _____ goes up
Respiration
Low blood pressure _____ rate of respiration
Increase
If something irritates lungs (you cough) leading to ______
Immediate cesstation
