Diffusion of Pulmonary Gases and Gas Laws

Question 1

What is partial pressure?

Answer 1

• 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.

Question 2

Laws that govern passive diffusion?

Answer 2

• Dalton’s law

- Henry’s law

Question 3

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?

Answer 3

Daltons law

Question 4

O2 must dissolve in the _______

Answer 4

Plasma of the pulmonary capillaries before it can diffuse into the Hgb inside RBC

Question 5

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?

Answer 5

Henry’s law

Question 6

What is like dissolves like?

Answer 6

Molecules typically are most soluble in solvents with similar polarity.

Question 7

_____ is 24 times more soluble than O2 in blood plasma.

Answer 7

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.

Question 8

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?

Answer 8

Graham’s law

Question 9

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.

Answer 9

Fick’s law

Question 10

The exchange of o2 and co2 between the alveolar air & pulmonary blood occurs in ________

Answer 10

Passive diffusion

Question 11

78.6% nitrogen, move two spaces left.
.786 x 760mmhg=597.4mmhg
(calc example of daltons law)

Answer 11

Nitrogen has highest partial pressure in atmosphere

Question 12

____ 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.

Answer 12

O2

Question 13

Greater the surface area the _____ the gas transfer rate

Answer 13

Higher (ficks law)-Directly proportional

Question 14

The thinner the membrane the _____ it diffuses

Answer 14

Quicker.(ficks law). Inversely proportional.

Question 15

The higher the molecular weight of gas the _____ the gas transfer rate.

Answer 15

lower. ficks law. inversely proportional.

Question 16

Gas transfer is ______ when pp is higher. Faster the transfer.

Answer 16

Higher. ficks law. Directly proportional.

Question 17

ARD’s?

Answer 17

Lungs full of fluid, meaning less surface area for gas transfer.

Question 18

v1/t1=v2/t2 is what? In the winter when pressure in something decreases it was related to the temp decreasing like tire pressure.

Answer 18

Charles law

Question 19

Couple ways to drop metabolic demand?

Answer 19

*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.

Question 20

The more _______ you are the higher chance for edema

Answer 20

Hemodilated

Question 21

Diffusion will happen ___________________ until both sides are the same O2 goes in or out and CO2 goes in or out.

Answer 21

In one direction or the other

Question 22

Due to ______ you will still have Co2 in alvioli

Answer 22

Dead spaces

Question 23

Atrial blood is ______

Venous blood is______

Answer 23

• Atrial-Oxygenated

* Venous-Deoxygenated

Question 24

Transit time of blood in capillaries?

Answer 24

.75 seconds (see diagram)-same for co2

Question 25

How long to fully saturate hemoglobin molecule with O2?

Answer 25

.25 seconds(see diagram)-same for co2

Question 26

Hemoglobin carries ___ and ___. Each molecule capable of binding to one molecule.

Answer 26

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

Question 27

_____ is the most important factor that determines how much o2 binds to hgb.

Answer 27

pO2

Question 28

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.

Answer 28

Left shift.

Question 29

O2 hemoglobin dissociation curve has _______ binding.

Answer 29

Non linear

Question 30

_______ of o2 is the most important factor that determines how much o2 gets bonded to hemoglobin

Answer 30

Partial pressure. Pp dictates this binding.

Question 31

p50 is normally ____mmHg

Answer 31

27mmHg

Question 32

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?

Answer 32

Right shift

Question 33

DPG helps control _____. When higher amounts it decreases ______.

Answer 33

Affinity

Question 34

What is the bohr effect?

Answer 34

The effect of pco2 and ph on the oxyhemoglobin curve.

Question 35

3 main forms CO2 is transported?

Answer 35

• Dissolved co2 in blood plasma (7%)
• Carbamino compounds (23%)mostly bound to hgb. (haldane effect)
• Bicarbonate ions (70%)

Question 36

What is the Haldane effect?

Answer 36

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.

Question 37

Cooling gas ______ solubility. Inverse relationship (temp and gas solubility.)

Answer 37

Increases

Question 38

Hypothermia _____ co2 production

Answer 38

decreases

Question 39

In hypothermia there is _____ affinity of hemoglobin with o2.

Answer 39

Increased. less o2 released to tissues. Left shift of oxygen-hemoglobin dissociation curve.

Question 40

What are the 3 areas in the respiratory center?

Answer 40

• Medullary rhythmicity area(control basic rhythm of respiration)
• Pneumotaxic area (more rapid breathing rate, involuntary)
• Apneustic area (slower breathing rate, involuntary)

Question 41

Important to know that when pnemotaxic are is ______ the apneustic area is _____ and vis a versa.

Answer 41

Stimulated, Inhibited.

Respiration is both voluntary and involuntary

Question 42

Certain chemical stimuli alter how quickly and/or deeply we breath. Name 2 peripheral chemoreceptors

Answer 42

• Aortic bodies

* Carotoid bodies

Question 43

Blowing off too much co2 can ______ the brain

Answer 43

Vasoconstrict

Question 44

Hypoventilation

Answer 44

Hypercapnia/hypercarbia-abnormally elevated CO2 in blood.

Question 45

Hyperventilation

Answer 45

Hypocapnia (hypocarbia)- rapid and deep breathing. Reduced CO2 in blood

Question 46

By moving joints muscles you can activate

Answer 46

Proprioceptor stimulation of respiration

Question 47

Temp goes up so does ______

Answer 47

Rate and depth

Question 48

Pain, if something hurts _____ goes up

Answer 48

Respiration

Question 49

Low blood pressure _____ rate of respiration

Answer 49

Increase

Question 50

If something irritates lungs (you cough) leading to ______

Answer 50

Immediate cesstation