Chapter 13

Question 1

what are 2 factors the body’s supply of oxygen depends on? *

Answer 1

1. concentration of gases in ambient air

2. partial pressure of gases in ambient air

Question 2

what are the concentration of gases in ambient air at sea level? *

Answer 2

20. 93% O2
21. 04% N2
22. 03% CO2

Question 3

what is a torr?

Answer 3

pressure of air molecules that raises a column of mercury in a barometer to a height of 760 mm

Question 4

what is partial pressure?

Answer 4

molecules of each specific gas in a mixture of gases exert their own partial pressure

Question 5

how do you calculate partial pressure?

Answer 5

partial pressure = percentage concentration of a specific gas / total pressure of gas mixture

Question 6

what does PAO2 stand for? *

Answer 6

partial pressure of O2 in alveolar chambers

Question 7

what does PaO2 stand for? *

Answer 7

partial pressure of O2 in arterial blood

Question 8

what does SaO2% stand for? *

Answer 8

percent saturation of O2 arterial blood with O2

Question 9

what does PvCO2 stand for? *

Answer 9

partial pressure of CO2 in venous blood

Question 10

what does a-VO2 diff stand for? *

Answer 10

arterial-mixed venous oxygen differences

Question 11

what is henry’s law?

Answer 11

mass of a gas that dissolves in a fluid at a given temperature varies in direct proportion to pressure of gas over the liquid

Question 12

what are 2 factors that govern the rate of gas diffusion into a fluid? *

Answer 12

1. pressure differential between gas above the fluid and gas dissolved in fluid
2. solubility of gas in the fluid

Question 13

what does it mean to have a higher total barometric pressure?

Answer 13

more ease of gas moving from high to low

Question 14

how fast does alveolar gas-blood gas equilibrium occur?

Answer 14

0.25 seconds

Question 15

what are 2 factors that impair gas transfer capacity at the alveolar-capillary membrane?

Answer 15

1. buildup of a pollutant layer that “thickens” the alveolar membrane
2. reduction in alveolar surface area

Question 16

what is the PO2 and PCO2 in active muscles during vigorous exercise?

Answer 16

PO2 falls toward 0 mmHg, making the pressure gradient very large so that O2 is driven into muscles

PCO2 approaches 90 mmHg

Question 17

why does alveolar ventilation couple tightly to metabolic demand?

Answer 17

to maintain a constant alveolar gas composition constant

Question 18

what are 2 ways that blood transports oxygen?

Answer 18

1. physical solution dissolved in the fluid portion of blood (plasma)
2. loose combination with hemoglobin

Question 19

what are 3 functions of O2 transported in physical solution?

Answer 19

1. establishes PO2 of plasma and tissue fluids
2. helps regulate breathing, particularly at altitude
3. determines O2 loading of hemoglobin in lungs and subsequent release in tissues

Question 20

what is hemoglobin?

Answer 20

iron-containing globular protein pigment

composed of 4 subunit polypeptide chains

Question 21

why do men have high Hb concentration levels?

Answer 21

relates to stimulating effects on red blood cell production of testosterone

Question 22

how many mL of O2 is in 1 gram of Hb?

Answer 22

1.34 mL

Question 23

what is the gold standard for examining O2 capacity?

Answer 23

Hb mass testing

Question 24

what is microcytic anemia? *

Answer 24

normal RBC levels but they are smaller cells

Question 25

what are the effects of iron deficiency anemia on athletes?

Answer 25

significant decrease in iron availability to decrease hemoglobin concentration

reduces the blood O2 carrying capacity

diminishes a person’s ability to sustain mild-intensity aerobic exercise

Question 26

what is cooperative binding?

Answer 26

the joining of O2 with Hb

Question 27

what is the relationship between pressure and Hb saturation with O2?

Answer 27

as pressure increases, saturation of Hb with O2 increases

Question 28

what is the relationship between temperature and Hb saturation with O2?

Answer 28

as temperature increases, saturation of Hb with O2 decreases

Question 29

what is the optimal temperature for aerobic performance and why?

Answer 29

8-10 degrees

if the blood is cold, hemoglobin can’t leave which hinders performance

Question 30

what is the relationship between acidity and Hb saturation with O2?

Answer 30

as acidity in blood increases, saturation of Hb with O2 decreases

Question 31

what is the bohr effect? *

Answer 31

states that any increase in plasma acidity and temperature causes the oxyhemoglobin dissociation curve to shift downward and to the right

indicates that [H+] and CO2 alter hemoglobin’s molecular structure to decrease its O2 binding affinity

Question 32

what is a-vO2 difference?

Answer 32

the difference between oxygen content of arterial blood and mixed-venous blood

Question 33

where do red blood cells get its energy?

Answer 33

anaerobic glycolysis, because it has no mitochondria, which produces the compound 2,3-diphosphoglycerate (2,3-DPG)

Question 34

what happens when 2,3-DPG and Hb bind?

Answer 34

reduces Hb affinity for O2 causing greater O2 release to tissues

Question 35

what are 3 ways blood carries CO2? *

Answer 35

1. physical solution in plasma (7%)
2. combined with hemoglobin (carbamino hemoglobin) within red blood cells (23%)
3. as plasma bicarbonate (70%)