Chapter 37

Question 1

What is unique about the respiratory tract?

Answer 1

-it is a continuation of the external environment

Question 2

What is Dalton’s law?

Answer 2

-each gas in a mixture of gases exerts its own partial pressure as if no other gases were present

Question 3

How do you calculate the partial pressure of a gas?

Answer 3

-by the concentration of the gas to the mixture

Question 4

What are the partial pressures of the atmospheric gases?

Answer 4

• Nitrogen: 78% or 590mmHg
• Oxygen: 21% or 160mmHg
• Carbon Dioxide: .04% or .3mmHg

Question 5

What is Henry’s law?

Answer 5

-the quantity of a gas that will dissolve in a liquid (blood) is proportional to the partial pressure of the gas and its solubility coefficient

Question 6

How does partial pressure of a gas relate to partial pressure of a liquid?

Answer 6

-the higher the partial pressure, the more gas that will dissolve in the liquid

Question 7

How does the bends relate to Henry’s law?

Answer 7

-the pressure is much greater under water so more gas (nitrogen) is dissolved into the blood which then travels to the brain

Question 8

What is external respiration?

Answer 8

• respiration in the lungs
• oxygen from alveoli into the blood
• carbon dioxide from blood into the alveolie

Question 9

What is internal respiration?

Answer 9

• respiration in the tissues
• oxygen from blood to tissues
• carbon dioxide from tissues to blood

Question 10

What is the partial pressure of oxygen in an alveolus?

Answer 10

-100mmHg

Question 11

How does the partial pressure of oxygen in the pulmonary capillary change as it surrounds the alveolus?

Answer 11

-the oxygen in the capillary goes from 40mmHg to 100mmHg

Question 12

What is the partial pressure of carbon dioxide in an alveolus?

Answer 12

-40mmHg

Question 13

How does the partial pressure of carbon dioxide change as the pulmonary capillary surrounds the alveolus?

Answer 13

-the carbon dioxide in the capillary goes from 46mmHg to 40mmHg

Question 14

What is the partial pressure of oxygen in tissue?

Answer 14

-40mmHg

Question 15

How does the partial pressure of oxygen change as a systemic capillary enters the tissue?

Answer 15

-the oxygen in the tissue goes from 40mmHg to 100mmHg

Question 16

What is the partial pressure of carbon dioxide in tissue?

Answer 16

-46mmHg

Question 17

How does the partial pressure of carbon dioxide change as a systemic capillary enters the tissue?

Answer 17

-the carbon dioxide in the tissue goes from 46mmHg to 40mmHg

Question 18

What influences the rate of gas exchange in external respiration?

Answer 18

• partial pressure difference of gases
• surface area available for gas exchange
• diffusion distance
• molecular weight and solubility of gases

Question 19

What is hemoglobin?

Answer 19

-a protein structure in red blood cells that carries oxygen

Question 20

What is the structure of a hemoglobin?

Answer 20

• 4 polypeptide chains

- 4 iron-containing heme groups

Question 21

How many oxygen molecules can bind to one hemoglobin?

Answer 21

-4

Question 22

Where does oxygen bind to?

Answer 22

-iron-containing heme group

Question 23

Where does carbon dioxide bind to?

Answer 23

-the polypeptide chain

Question 24

How much oxygen dissolves in the plasma?

Answer 24

-1.5%

Question 25

How much oxygen binds/associates with hemoglobin?

Answer 25

-98.5%

Question 26

What is percent saturation?

Answer 26

-how many oxygen molecules are carried in a certain solution

Question 27

What is hemoglobin saturation do?

Answer 27

-increases percent saturation of oxygen

Question 28

What influences percent saturation?

Answer 28

- partial pressure of oxygen - higher pressure = higher hemoglobin saturation - lower pressure = lower hemoglobin saturation

Question 29

What else influences oxygen saturation?

Answer 29

- acidity - lower pH = lower oxygen saturation; oxygen goes to tissues - higher pH = higher oxygen saturation; oxygen remains with hemoglobin

Question 30

What is the Bohr effect?

Answer 30

-the shift between high and low pH causing shift in oxygen saturation

Question 31

What does a decreased blood pH cause? What does this mean?

Answer 31

- a decrease in oxygen saturation | - more oxygen will leave hemoglobin to enter the tissues

Question 32

What are three ways that carbon dioxide can be transported?

Answer 32

- dissolved in plasma and transported as a solute (10%) - carbamino compounds bound to a hemoglobin (20-25%) - bicarbonate (65-70%)

Question 33

What are the percentages of carbon dioxide that are transported in each way?

Answer 33

- dissolved in plasma and transported as a solute (10%) - carbamino compounds bound to a hemoglobin (20-25%) - bicarbonate (65-70%)

Question 34

What is a carbamino compound?

Answer 34

-carbon dioxide will bind with the amino acids of hemoglobin

Question 35

What is a bicarbonate?

Answer 35

-carbon dioxide associates with water to make HCO3 and H

Question 36

How does carbon dioxide influence blood pH?

Answer 36

- increasing CO2 increases [H] - this increases the acidity - which lowers the pH

Question 37

An increase in carbon dioxide would cause what change in pH?

Answer 37

-lowering of pH to become more acidic

Question 38

How does carbon dioxide contribute to the Bohr effect?

Answer 38

- more partial pressure of carbon dioxide lowers pH | - this causes more oxygen to go into tissue

Question 39

How does temperature influence oxygen saturation?

Answer 39

- temperature causes a right shift | - increase of temperature increases CO2 which lowerspH

Question 40

An increase in temperature would cause (more/less) oxygen to be delivered to tissues?

Answer 40

- more | - because the blood would become more acidic