Carbon Dioxide Transport Flashcards Preview

Apex 1 - 2 Respiratory II: Physiology (24) > Carbon Dioxide Transport > Flashcards

Flashcards in Carbon Dioxide Transport Deck (36)
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1

What's the primary by-product of aerobic metabolism?

Carbon dioxide

 

2

Carbon dioxide is the primary by-product of aerobic metabolism. -------- blood transports it to the lungs, where it's excreted into the atmosphere.

A. Venous blood 

B.  Arterial blood

Venous blood

3

PvC02 is about ----- mmHg higher than PaC02

5 mmHg

4

Why is venous blood more acidic than arterial blood?

PvC02 > PaC02

(by 5 mmHg)

5

What's Arterial blood pH?

7.40

6

What's Venous blood pH?

7.36

7

What are the three Mechanisms of CO2 Transport?

Bicarbonate

Bound to Hemoglobin

Dissolved in the Plasma

8

What % of venous CO2 is transported as Bicarbonate?

70%

9

What % of venous CO2 is transported Bound to Hemoglobin?

23%

10

What % of venous CO2 is transported Dissolved in the Plasma?

7%

11

The vast majority of CO2 in the blood is in the form of:

Bicarbonate

(70%)

12

The vast majority of CO2 in the blood is in the form of bicarbonate. Write the chemical reaction that transforms CO2 into Bicarbonate:

H2O + CO2 H2CO3 H+ + HCO3-

 

13

The vast majority of CO2 in the blood is in the form of bicarbonate

[H2O + CO2 H2CO3 H+ + HCO3-]

Which enzyme, in erythrocytes, is required for this reaction to take place?

 

Carbonic anhydrase

14

Carbonic anhydrase is present in

A. Erythrocyte

B. Plasma

Erythrocyte

(Carbonic anhydrase is present in the erythrocyte but not in the plasma)

15

In the presence of carbonic anhydrase, CO2 and H20 react to form:

Carbonic acid or H2C03

[H2O + CO2 H2CO3 H+ + HCO3-]

16

Carbonic acid rapidly dissociates into:

H+ and HC03-

[H2O + CO2 H2CO3 H+ + HCO3-]

17

Carbonic acid rapidly dissociates into H+ and HC03-. The H+ is buffered by

 

Hemoglobin (Hb)

H+ + Hb- HbH

18

Carbonic acid rapidly dissociates into H+ and HC03-. The HC03- is transported to the

Plasma

 

19

Carbonic acid rapidly dissociates into H+ and HC03-. The HC03- is transported to the plasma to function as

Buffer

20

Carbonic acid rapidly dissociates into H+ and HC03-. The H+ is buffered by hemoglobin and the HC03- is transported to the plasma to function as a buffer. Which ion is transported into the erythrocyte to maintain electroneutrality?

Chloride ion (Cl-)

21

Carbonic acid rapidly dissociates into H+ and HC03-. The H+ is buffered by hemoglobin and the HC03- is transported to the plasma to function as a buffer. Chloride ion (Cl-) is transported into the erythrocyte to maintain electroneutrality. 

What is this phenomenon called?

Chloride or Hamburger shift

22

How does the  Chloride/Hamburger shift operate in the lungs?

in reverse

(HCO3- moves from the plasma to the erythrocyte while Cl- moves from erythrocyte to plasma)

23

Notice that the chloride shift adds osmotically active ------ to the erythrocyte in the venous circulation

Chloride ions (Cl-)

24

Notice that the chloride shift adds osmotically active ions (Cl-) to the erythrocyte in the venous circulation. Water follows isosmotically, causing the erythrocyte to

Swell

25

Notice that the chloride shift adds osmotically active ions (Cl-) to the erythrocyte in the venous circulation. Water follows isosmotically, causing the erythrocyte to swell. This increases

A. cell volume relative to plasma volume

B. plasma volume relative to cell volume

cell volume relative to plasma volume

26

Notice that the chloride shift adds osmotically active ions (Cl-) to the erythrocyte in the venous circulation. Water follows isosmotically, causing the erythrocyte to swell. This increases cell volume relative to plasma volume and explains why

A. arterial hematocrit is higher than venous hematocrit.

B. venous hematocrit is higher than arterial hematocrit.

Venous hematocrit is higher than arterial hematocrit.

27

How much higher is venous hematocrit compared to arterial hematocrit?

~ 3% higher

28

Why is venous hematocrit ~ 3% higher than arterial hematocrit?

Chloride / Hamburger shift

29

Where in the body is the Chloride / Hamburger shift reversed?

Lungs

30

What % of Carbon dioxide is bound to Hemoglobin?

23%