Resp. 4 - Gas transport

Question 1

The only true measure of O2 in our blood is

Answer 1

dissolved O2 in blood plasma and the oxygen bound to hemoglobin

Question 2

O2 Transport in Blood

Answer 2

1. Dissolved (~2%)

2. Bound to Hemoglobin (~98%)

Question 3

• As PO2 changes, so does

Answer 3

saturated hemoglobin%.

Question 4

What factories effect PO2 saturation

Answer 4

• Temp, Ph, and PCO2 also all effects % of saturated hemoglobin

Question 5

O2 Transport in Blood- Dissolved

Answer 5

Content of arterial [O2] dissolved (ml O2/ dl blood) = 0.3 ml O2 / do blood

Question 6

O2 Transport in Blood- Hemoglobin

Answer 6

Content of arterial [O2] Hb (ml O 2/ dl blood) = 20 ml/dl

Question 7

• [O2]arterial =

Answer 7

• [O2]arterial = dissolved + Hb
• = 0.3 ml/dl + 20 ml/dl
• = 20.3 ml/dl

Question 8

Venous O2 Content

Answer 8

• [O2 ]venous = 1.35 x 15 x 75%

* [O2]venous = ~15 ml/dl

Question 9

Hemoglobin Saturation in Hb-O2 Dissociation Curve:

• From the hemoglobin dissociation curve:
  Oxygen capacity

Answer 9

N

Question 10

Hemoglobin saturation →

Answer 10

The percentage of the available hemoglobin binding sites that have the oxygen attached.

• At the level of the arterial blood where PO2 is 100 mmHg, hemoglobin saturation is about 97.5%

Question 11

Oxygen capacity →

Answer 11

the maximum amount of oxygen that can be combined with hemoglobin

• Depends on how much hemoglobin is present in the blood; a change in the amount of hemoglobin will change the oxygen capacity

Question 12

• At the level of the arterial blood where PO2 is 100 mmHg, hemoglobin, saturation is about

Answer 12

97.5%

Question 13

• At the level of the mixed venous blood were PO2 is about 40 mmHg, hemoglobin saturation is about

Answer 13

75%

Question 14

At a higher temp, hemoglobin carries

Answer 14

more Oxygen bound to its self

Question 15

At a lower temp, hemoglobin carries

Answer 15

Less oxygen bound to itself, but more O2 is in the tissue.

Question 16

creating a solution that’s acididoc, high in

Answer 16

CO2 (61) and lower pH. With 50% saturation, more O2 is free to dissociate and diffuse into tissue

Question 17

creating a more basic solution, there’s

Answer 17

more O bound, so less to diffuse into the tissue where you need it.

Question 18

CO 2 Transport in Blood

Answer 18

• 1. Dissolved (10%)
• 2. Carbamino Hemoglobin (20%)
• 3. Bicarbonate (70%)

Question 19

Bicarbonate rxn

Answer 19

CO2 + H2O —> H2CO3 —-> H+ + HCO3-

Rxn catalyst: carbonic anhydrase
Rain is reversible

Question 20

What percent of CO2 coming in form the tissue, going into the plasma does what

Answer 20

• 11% dissolves into plasma

- 89% goes into the RBC

Question 21

Of the 11% of CO2 entering the plasma, what happened to the 11%.

Answer 21

• 6% dissolves in plasma
• <1% reacts with R-NH2 = H+
• 5% forms bicarbonate + H+ (slow rxn)

Question 22

What happens to that 89% of CO2 entering the RBC ?

Answer 22

• 4% dissolved
• 64% form bicarbonate and H+ (with carbonic anhydrase)
• 21% forms carbon hemoglobin and H+

Question 23

How does the CO2 form bicarbonate in the RBC, and what happens to it?

Answer 23

CO2 reacts with OH- that comes form dislocated H2O entering the RBC, bicarbonate then it exchanged with Cl- ions (electro neutral)

Question 24

Chloride (hamburger) shift

Answer 24

The bicarbonate produced in the RBC is then exchanged for Cl- ions through a transporter because this facilitated the uptake of CO2.

Question 25

Of that 21% of CO2 forming carbon hemoglobin and H+, what happens to the H+

Answer 25

The H+ binds to the Hb instead of the Hb binding to the O2, therfore allowing the O2 to diffuse into the tissue where its needed (Haldane effect)

Question 26

Haldane effect

Answer 26

Hb bound to H+ makes O2 available to diffuse into the Periphery, so Hb has a higher affinity for H+, causing a disassociation of O2 bound to Hb and to make it available to diffuse into tissues where you need it (dissolves into plasma first, then goes into tissues).

Question 27

The 3 purposes H+ has by binding to Hb

Answer 27

* Hb bound to H+ makes O2 available to diffuse into the Periphery, causing a disassociation of O2 bound to Hb and to make it available to diffuse into tissues where you need it. * important for acid base balance. Free H+ makes pH stable. Hb acts as BUFFER * Hb high affinity for H+ facilitates CO2 uptake, cuz ur reducing one of the producing, increasing I demand for CO2

Question 28

What does an increase in alveolar ventilation do in terms of CO2?

Answer 28

Removes / decreases CO2

Question 29

Increasing ventilation removes CO2 by

Answer 29

exhaling into the environment, reversing the rxn direction into using up H+ to product CO2, so you compensate for being acidionc by increasing the pH.

Question 30

When is an increase in alveolar ventilation used in terms of Ph?

Answer 30

If the pH is to low (acidic) then an increase in ventilation will DEC CO2 = use more H+ to balance rxn, making less acidic

Question 31

When is a decrease in alveolar ventilation done in terms of CO2 ?

Answer 31

To increase of add CO2

Question 32

Having to much alkaline in the blood, you reduce

Answer 32

ventilation = adding CO2 = making more H+ (acidic)

Question 33

When is a decrease in alveolar ventilation done in terms of pH ?

Answer 33

If pH is too high, to basic, DEC ventilation to INC CO2 = uses more CO2 to produce MORE H+ to drop pH and make more acidic