CHAPTER 40 TRANSPORT of O2 and CO2 in Blood and Tissue Fluids

Question 1

General Information about TRANSPORT of O2 & CO2–1

O2 and CO2 move from one point to another by diffusion and the primary cause of diffusion (under normal conditions) is the _________in partial pressures—higher in one area and lower in the other.

Answer 1

difference

Question 2

General Information about TRANSPORT of O2 & CO2–2

O2 diffuses from the alveoli into the pulmonary capillary blood because PO2 is __________ in the alveoli than in the capillary blood. As the blood flows from the pulmonary capillaries to peripheral tissues, these PO2 differences will continue to exists so that O2 can diffuse from the blood into the tissues.

Answer 2

higher

Question 3

General Information about Transport of O2 & CO2–3

After O2 enters the peripheral tissues, it reacts with _________ (mainly CHOs) to form large quantities of CO2. This causes a high PCO2 inside the cells which causes CO2 to diffuse into the lower PCO2 area of the peripheral capillaries.

Answer 3

nutrients

Question 4

General Information about Transport of O2 & CO2–4

Once blood returns to the lungs, CO2 diffuses out of the pulmonary capillaries into the alveoli because the PCO2 is __________in the alveoli than in the blood

Answer 4

lower

Question 5

Transport of O2 in Arterial Blood—1

1–About 98% of the blood that enters the left atrium from the lungs passes through the pulmonary capillaries and becomes oxygenated with a PO2 of 104 mmHg.

2—The other 2% of the blood supplied the deep tissues of the lungs—this is called “_____ _______” meaning that the blood was shunted past the gas exchange area.

Answer 5

shunt flow

Question 6

Diffusion of&raquo_space;O2

Answer 6

interstitial

Question 7

Diffusion of&raquo_space;CO2

Answer 7

20

Question 8

Diffusion of&raquo_space;CO2

Answer 8

artery

venous

Question 9

Role of Hb in O2 Transport

1–Under normal conditions, about __% of the O2 transported from the lungs to the peripheral tissues is carried in a chemical bond with Hb. The remaining __% of O2 is transported in a dissolved state in the water of the plasma.

2–The O2 molecule binds loosely and reversibly with the _______ portion of the Hb molecule.

3–When PO2 is HIGH (as in the pulmonary capillaries), O2 binds with Hb but when PO2 is LOW (as in the peripheral tissues), O2 is released from the Hb.

Answer 9

97

3

heme

Question 10

Oxygen-Hemoglobin Dissociation Curve

1— as PO2 increases,
more O2 binds to Hb. This is called the
________ __________ of hemoglobin

2—Since the PO2 is about 95 mmHg as the blood leaves the lungs and enters the systemic (peripheral) arteries, from the
curve the usual oxygen ________ of systemic arterial blood averages 97%

3—Conversely, normal venous blood returning from the peripheral tissues to the lungs in venous blood has a PO2 of 40 mmHg which translates to saturation of hemoglobin
averaging 75% at 40 mmHg.

Answer 10

percent saturation

saturation

Question 11

Factors That Shift the Curve

1—A number of factors can shift the curve to the right or to the left. The example on the curve is a change in blood pH— if 7.4 is normal pH, 7.2 is slightly acidic = RIGHT and 7.6 is slightly basic = LEFT. The other factors listed can only shift the curve to the right.

2—The shift to the right and downward as a result of increased H+ or increased CO2 is called the _____ ______

3–This shift to the right forces O2 away from the Hb and into the cells—delivering more O2 to the tissues that need it.

Answer 11

Bohr Effect.