Chapter 24

Question 1

Dalton’s Law of Partial Pressures - R

Answer 1

Total pressure exerted by a mixture of gases is the sum of the pressures exerted by each gas

Question 2

Henry’s Law

Answer 2

When a mixture of gases is in contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure

Question 3

what regulates the rate of loading and unloading of O2

Answer 3

Po2
Temperature
Blood pH
Pco2

Question 4

factors that influence external respiration

Answer 4

Partial pressure gradients and gas solubilities

Ventilation-perfusion coupling

Question 5

what type of process is external respiration?

Answer 5

a passive process

Question 6

drop in Pco2 levels

Answer 6

hypocapnia

Question 7

rise in Pco2 levels

Answer 7

hypercapnia

Question 8

centers that control the depth and rate of breathing

Answer 8

Pontine Respiratory Center

Medullary Respiratory Center

Question 9

Apnea

Answer 9

a complete stop in breathing

Question 10

3 ways that CO2 is transported in the blood

Answer 10

dissolved in plasma
bound to hemoglobin
as bicarbonate ions

Question 11

the weakening of the Hb-oxygen bond caused by a decline in pH - R

Answer 11

Bohr effect

Question 12

how much more soluble if CO2 in water compared to O2?

Answer 12

20x

Question 13

respiratory and hematopoietic adjustments to altitude

Answer 13

Acclimatization

Question 14

above what altitude does acute mountain sickness occur?

Answer 14

8000 feet

Question 15

symptoms of altitude sickness

Answer 15

Headaches, shortness of breath, nausea, and dizziness

Question 16

function of the Hering-Breuer Reflex

Answer 16

to prevent over inflation of the lungs

Question 17

how does the Hering-Breuer Reflex work?

Answer 17

Stretch receptors in the pleurae and airways are stimulated by lung inflation
Inhibitory signals to the medullary respiratory centers end inhalation and allow expiration to occur

Question 18

effect of a decrease in pH on ventilation

Answer 18

increased pulmonary ventilation

Question 19

effect of an increase in pH on ventilation

Answer 19

decreased pulmonary ventilation

Question 20

Haldane effect

Answer 20

The amount of CO2 transported is affected by the Po2

Question 21

what is the direction of the diffusion of gases at capillaries in the tissues?

Answer 21

oxygen out of blood

CO2 into blood

Question 22

dominant method of CO2 transport

Answer 22

dissolved in plasma as bicarbonate ions

Question 23

Forces that maintain the negative pressure in Pip

Answer 23

1. elasticity of the lungs
2. surface tension in alveoli
3. chest wall pulling action

Question 24

what level of pH will will make oxygenated hemoglobin release oxygen more readily?

Answer 24

decreased

Question 25

what will holding breath for 60 sec do?

Answer 25

increase alveolar pCO2

Question 26

where is partial pressure of CO2 higher than oxygen?

Answer 26

blood leaving right ventricle

Question 27

chloride ions moving into or out of the red blood cell

Answer 27

chloride shift

Question 28

the most important stimulus for breathing

Answer 28

body’s need to rid itself of CO2

Question 29

when CO2 is accumulated in the blood the pH is…?

Answer 29

decreased

Question 30

how is most oxygen transported?

Answer 30

by iron in Hb

Question 31

what does alveolar gas have a higher concentration of

Answer 31

CO2

Question 32

bohr effect

Answer 32

low pH decreases the affinity of hemoglobin for oxygen

Question 33

what PCO2 increased the affinity of hemoglobin for oxygen?

Answer 33

low PCO2

Question 34

where is carbonic anhydrase loacted?

Answer 34

inside red blood cells

Question 35

hypocapnia

Answer 35

drop in Pco2 levels

Question 36

hypercapnia

Answer 36

rise in Pco2 levels

Question 37

a complete stop in breathing

Answer 37

Apnea

Question 38

how much oxygen is unloaded?

Answer 38

20-25%