Post Midterm

Question 1

A molecule that blocks the activity of carbonic anhydrase would

Answer 1

cause an increase in blood pH.

Question 2

A student in your lab volunteers to enter a hypoxic breathing chamber for 10 minutes, and his alveolar PO2 drops to 50 mm Hg. What other change would occur?

Answer 2

decrease in arterial PCO2

Question 3

Active expiration is produced by contraction of

Answer 3

abdominal muscles and internal intercostals.

Question 4

Air entering the body is filtered, warmed, and humidified by the

Answer 4

upper respiratory tract.

Question 5

Air moves into the lungs because

Answer 5

the gas pressure in the lungs is less than outside pressure

Question 6

Air moves out of the lungs because

Answer 6

the volume of the lungs decreases with expiration.

Question 7

Alveolar ventilation refers to the

Answer 7

movement of air into and out of the alveoli.

Question 8

An increase in P CO2 would cause

Answer 8

the bronchioles to dilate and the systemic arterioles to dilate

Question 9

An increase in the level of carbon dioxide in the blood will

Answer 9

increase the rate of breathing.

Question 10

At a P O2 of 70 mm Hg and normal temperature and pH, hemoglobin is ________% saturated with oxygen.

Answer 10

over 90

Question 11

Boyle’s law states that gas volume is

Answer 11

inversely proportional to pressure.

Question 12

Carbon dioxide is more soluble in water than oxygen. To get the same amount of oxygen to dissolve in plasma as carbon dioxide, you would have to

Answer 12

increase the partial pressure of oxygen

Question 13

Dalton’s law states that

Answer 13

in a mixture of gases like air, the total pressure is the sum of the individual partial pressures of the gases in the mixture.

Question 14

Damage to the type II cells of the lungs would contribute to

Answer 14

alveolar collapse

Question 15

During normal expiration,

Answer 15

elastic recoil of stretched muscles helps return the thorax to its resting volume.

Question 16

Flow of air

Answer 16

is directly proportional to a pressure gradient, and flow decreases as the resistance of the system increases

Question 17

If a student inhales as deeply as possible and then blows the air out until he cannot exhale any more, the amount of air that he expelled is his

Answer 17

vital capacity

Question 18

Increasing the alveolar ventilation rate will

Answer 18

increase the partial pressure of oxygen in the alveoli

Question 19

Match the factor with its effect on the affinity of hemoglobin for oxygen.

Increased Temperature

Answer 19

Decrease

Question 20

Match the factor with its effect on the affinity of hemoglobin for oxygen.

Increased PCO2

Answer 20

Decrease

Question 21

Match the factor with its effect on the affinity of hemoglobin for oxygen.

Increased pH

Answer 21

Increase

Question 22

Most of the carbon dioxide in the blood is transported as

Answer 22

bicarbonate ions.

Question 23

Most of the oxygen transported by the blood is

Answer 23

bound to hemoglobin

Question 24

Of the factors that influence diffusion of respiratory gases, the most variable and, therefore, important factor to consider is the

Answer 24

concentration gradient.

Question 25

Place the following structures of the respiratory tree in the order in which air passes through them. 1. secondary bronchi 2. bronchioles 3. primary bronchi 4. alveoli 5. terminal bronchioles

Answer 25

3, 1, 2, 5, 4

Question 26

Pulmonary ventilation refers to the

Answer 26

movement of air into and out of the lungs.

Question 27

Surfactant

Answer 27

helps prevent the alveoli from collapsing.

Question 28

The actual sites of gas exchange within the lungs are

Answer 28

alveoli.

Question 29

The expiratory neurons control the ________ muscles, whereas the inspiratory neurons control the ________ muscles.

Answer 29

abdominal and internal intercostal, diaphragm and external intercostal

Question 30

The lungs are enclosed in ________ membranes.

Answer 30

pleural

Question 31

The lungs are located in the ________ cavity.

Answer 31

thoracic

Question 32

The most important chemical regulator of respiration is

Answer 32

carbon dioxide

Question 33

The process by which dissolved gases are exchanged between the blood and interstitial fluids is

Answer 33

diffusion

Question 34

Type I alveolar cells

Answer 34

allow rapid diffusion of gases through their thin membranes.

Question 35

Type II alveolar cells

Answer 35

secrete a chemical known as surfactant

Question 36

Ventilation is also known as

Answer 36

Breathing

Question 37

When the diaphragm and external intercostal muscles contract,

Answer 37

the volume of the thorax increases.

Question 38

Which of the following characteristics makes hemoglobin's structure such a good match for its function as an oxygen carrier?

Answer 38

Each hemoglobin molecule can bind four oxygen molecules.

Question 39

Which of the following would make the oxygen-hemoglobin curve shift right?

Answer 39

increased H + concentration

Question 40

___________________ states that at a given tempurature, the amount of gas dissolved in a liquid is directly proportional to the partial pressure of that gas. Meaning that the concentration of gas in a liquid is directly proportional to the solubility and partial pressure of that gas. The greater the partial pressure of the gas, the greater the number of gas molecules that will dissolve in the liquid. The concentration of the gas in a liquid is also dependent on the solubility of the gas in the liquid.

Answer 40

Henry's Law