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Flashcards in chapter 18 Deck (29):
1

High carbon dioxide concentration in body fluids is called
A) carbonation.
B) hypercapnia.
C) hyperoxia.
D) hyperdioxia.
E) hypercarbia.

B) hypercapnia.

2

The partial pressure of oxygen in arterial blood is approximately ________ mm Hg.
A) 70
B) 45
C) 50
D) 40
E) 100

E) 100

3

The partial pressure of carbon dioxide in the cells of peripheral tissues is approximately ________
mm Hg.
A) 45
B) 50
C) 70
D) 40
E) 100

A) 45

4

Of the factors that influence diffusion of respiratory gases, the most variable and, therefore,
important factor to consider is the
A) membrane surface area.
B) diffusion distance.
C) membrane thickness.
D) concentration gradient.
E) electrical charge.

D) concentration gradient.

5

The process by which dissolved gases are exchanged between the blood and interstitial fluids is
A) external respiration.
B) diffusion.
C) breathing.
D) pulmonary ventilation.
E) cellular respiration.

B) diffusion.

6

The lung pathology most likely to result from certain kinds of heart disease is
A) emphysema.
B) lung cancer.
C) asthma.
D) pulmonary edema.
E) fibrotic lung disease.

D) pulmonary edema.

7

Hypoxia resulting from fluid accumulation in the alveoli that cannot be corrected by oxygen
therapy can lead to
A) fibrotic lung disease.
B) sudden infant death syndrome.
C) emphysema.
D) adult respiratory distress syndrome.
E) asthma.

D) adult respiratory distress syndrome.

8

If the partial pressure of oxygen in both air and water is 100 mm Hg, then the concentration of the
oxygen is the same in the air and water.
A) True
B) False

B) False

9

The variables of oxygen consumption, cardiac output, and blood oxygen content are unrelated.
A) True
B) False

B) False

10

Which of the following characteristics makes hemoglobin's structure such a good match for its
function as an oxygen carrier?
A) Each hemoglobin molecule can't be saturated by oxygen molecules.
B) Each hemoglobin molecule can bind one oxygen molecule.
C) Each hemoglobin molecule can bind two oxygen molecules.
D) Each hemoglobin molecule can bind four oxygen molecules.
E) Each hemoglobin binds irreversibly to an oxygen molecule.

D) Each hemoglobin molecule can bind four oxygen molecules.

11

Most of the oxygen transported by the blood is
A) carried by white blood cells.
B) dissolved in plasma.
C) bound to a plasma protein.
D) in ionic form as solute in the plasma.
E) bound to hemoglobin.

E) bound to hemoglobin.

12

At a PO2 of 70 mm Hg and normal temperature and pH, hemoglobin is ________% saturated with oxygen.
A) 75
B) 50
C) 10
D) over 90
E) 25

D) over 90

13

Which of the following would make the oxygen-hemoglobin curve shift right?
A) increased pH
B) increased H+ concentration
C) decreased CO2
D) decreased temperature
E) None of the answers are correct.

B) increased H+ concentration

14

Chronic hypoxia
A) can be caused by anemia.
B) shifts the HbO2 dissociation curve to the left.
C) increases 2,3-DPG production in blood and can result from anemia.
D) increases 2,3-DPG production in blood.
E) All of the answers are correct.

C) increases 2,3-DPG production in blood and can result from anemia.

15

Most of the carbon dioxide in the blood is transported as
A) carbaminohemoglobin.
B) solute dissolved in the cytoplasm of red blood cells.
C) bicarbonate ions.
D) carbonic acid.
E) solute dissolved in the plasma.

C) bicarbonate ions.

16

In the medulla oblongata, the nucleus tractus solitarius contains the ________ of neurons.
A) ventral respiratory group
B) pre-Botzinger complex
C) dorsal respiratory group
D) pontine respiratory group

C) dorsal respiratory group

17

The most important chemical regulator of respiration is
A) oxygen.
B) sodium ion.
C) hemoglobin.
D) bicarbonate ion.
E) carbon dioxide.

E) carbon dioxide.

18

An increase in the level of carbon dioxide in the blood will
A) decrease the rate of breathing.
B) increase the rate of breathing.
C) increase the pH of arterial blood.
D) decrease pulmonary ventilation.
E) decrease the alveolar ventilation rate

B) increase the rate of breathing.

19

The expiratory neurons control the ________ muscles, whereas the inspiratory neurons control the
________ muscles.
A) abdominal and internal intercostal, diaphragm and external intercostal
B) diaphragm and external intercostal, abdominal and internal intercostal
C) abdominal and external intercostal, diaphragm and internal intercostal
D) diaphragm and internal intercostal, abdominal and external intercostal
E) diaphragm and abdominal, intercostal internal and external

A) abdominal and internal intercostal, diaphragm and external intercostal

20

If the neural connections between the pons and medulla are severed, breathing will stop.
A) True
B) False

B) False

21

The Hering-Breuer reflex
A) alters pulmonary ventilation when the PCO2 changes.
B) functions to increase ventilation with changes in blood pressure.
C) alters pulmonary ventilation when the PO2 changes.
D) is an important aspect of normal, quiet breathing.
E) prevents overexpansion of the lungs.

E) prevents overexpansion of the lungs.

22

Protective reflexes of the lungs include
A) bronchoconstriction.
B) bronchodilation.
C) coughing.
D) bronchodilation and coughing.
E) coughing and bronchoconstriction.

E) coughing and bronchoconstriction.

23

Jill lives in St. Louis, which is close to sea level. She decides to spend a month of her summer
vacation working in the mountains outside of Denver. After a week in the mountains, what kinds
of changes would you expect to see as Jill adapts to the higher altitude?
A) decreased alveolar ventilation rate
B) decreased blood pressure
C) decreased PO2 in the alveoli
D) decreased hematocrit
E) All of the answers are correct.

C) decreased PO2 in the alveoli

24

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
A) decrease the alveolar ventilation rate.
B) decrease the temperature of the plasma.
C) increase the rate of plasma flow through the lungs.
D) decrease the partial pressure of nitrogen.
E) increase the partial pressure of oxygen.

E) increase the partial pressure of oxygen.

25

For maximum efficiency in loading oxygen at the lungs,
A) the PO2 should be about 70 mm.
B) the pH should be slightly acidic.
C) the temperature should be slightly lower than normal body temperature.
D) DPG levels in the red blood cells should be high.
E) All of the answers are correct.

C) the temperature should be slightly lower than normal body temperature.

26

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?
A) increase in alveolar PCO2
B) decrease in arterial pH
C) decrease in arterial PCO2
D) decrease in pH of cerebrospinal fluid
E) hypoventilation

C) decrease in arterial PCO2

27

A molecule that blocks the activity of carbonic anhydrase would
A) cause an increase in blood pH.
B) increase the amount of bicarbonate formed in the blood.
C) decrease the amount of carbon dioxide dissolved in the plasma.
D) interfere with oxygen binding to hemoglobin.
E) All of the answers are correct.

A) cause an increase in blood pH.

28

The chloride shift occurs when
A) hydrogen ions leave the red blood cells.
B) bicarbonate ions enter the red blood cells.
C) hydrogen ions enter the red blood cells.
D) carbonic acid is formed.
E) bicarbonate ions leave the red blood cells

E) bicarbonate ions leave the red blood cells

29

Blocking afferent action potentials from the chemoreceptors in the carotid and aortic bodies would
interfere with the brain's ability to regulate breathing in response to all EXCEPT which of the
following? A) changes in PCO2
B) changes in pH due to carbon dioxide levels
C) changes in blood pressure
D) changes in PO2
E) All of the answers are correct.

C) changes in blood pressure