Carbon Dioxide Transport And Excretion

Front 1

Diffusion of C02 from cells into tissue capillaries occurs how?

Back 1

C02 diffuses down its partial pressure gradient--diffusion equilibrium normally occurs

Front 2

Intracellular PC02 is ____; interstitialy PC02 is ______; PC02 of arterial blood entering the tissues is _____.

Back 2

46, 45, 40

Front 3

Transport of C02 in the blood- 3 forms?

Back 3

1. Co2 dissolved in plasma water
2. Bicarbonate ion
3. Carbaminohemoglobin

Front 4

At venous blood PC02 is ____, the amount of dissolved CO2 is about ________mL/100mL.

Back 4

45, 2.7

Front 5

Approximately what % of blood CO2 is transported as dissolved in plasma water?

Back 5

7%

Front 6

How is carbonic acid formed?

Back 6

Co2 in the blood reacts with water inside RBCs, the reaction is catalyzed by the enzyme carbonic anhydrase present in RBCs

Front 7

Carbonic acid ionizes to yield?

Back 7

hydrogen and bicarbonate ions
1) H+ is buffered by Hb
2. HCO3- diffuses out of the RBC in exchange for Cl-

Front 8

What % of blood CO2 is transported in bicarbonate?

Back 8

70%

Front 9

Carbaminohemoglobin is formed how?

Back 9

C02 reacts reversible with the terminal amine group of the hemoglobin molecule

Front 10

Approximatey what % of blood C02 is transported in carbaminohemoglobin?

Back 10

23%

Front 11

Describe the diffusion of C02 from pulmonary capillary blood into the alveolar gas?

Back 11

Co2 diffuses down its partial pressure gradient, PC02 of blood entering the pulmonary capillary is 45 mmHg; alveolar PC02 is 40 mmHg, diffusion equilibrium normally occurs

Front 12

What does the carbon dioxide "dissocation" curve relate?

Back 12

total C02 in the blood to PC02

Front 13

CO2 unloading in the lung is facilitated by?

Back 13

oxygen loading

Front 14

Haldane effect

Back 14

When oxygen binds with hemoglobin, C02 is released to increase C02 transport

Front 15

What causes Hb to become a stronger acid?

Back 15

Binding of oxygen to Hb

Front 16

If oxygen is binding to Hb what is displaced?

Back 16

C02 bound as carbaminohemoglobin

Front 17

What else is displaced due to oxygen binding to Hb and creating a stronger acid?

Back 17

H+ bound to Hb are also displaced and combine with bicarbonate to form carbonic acid which yields Co2 and H20

Front 18

In the tissue capillaries, what is different about the Haldane effect?

Back 18

It works in the opposite direction - oxygen unloading shifts the C02 dissocation curve to the left or upward (relative to its position in the lungs) and facilitates C02 uptake

Front 19

The amount of Co2 that can be released from blood in the lungs, and taken up by blood in the tissues, is ______ by the Haldane effect.

Back 19

Doubled

Front 20

What is the respiratory exchange ratio, or respiratory quotient (R)?

Back 20

is the ratio of C02 production to 02 consumption

Front 21

Normally at rest, how much oxygen per 100 mL blood is transported from the lung to the tissues? and how much C02 is transported from the tissues to the lungs?

Back 21

5 mL , 4 mL

Front 22

So if 5 mL is transported from lung into the tissues, and 4 mL is transported from tissues to the lungs, how would you describe C02 excretion?

Back 22

normally about 80% of oxygen uptake and R is 0.8

Front 23

The actual value of R depends on?

Back 23

the metabolic substrates being utilized for cellular ATP production

Front 24

If a person were using only carbohydrate for metabolism, R would be?

Back 24

1.0

Front 25

If a person were using only FA for metabolism, R would be?

Back 25

0.70

Front 26

For a person consuming a normal diet consisting of carb, fat, and protein, R is approximately?

Back 26

0.80