Ch32: Structure & Fn of the Pulmonary System

Question 0

1. Considering the sequence of structures through which air enters the pulmonary system, the pharynx is to trachea as the:
   a. bronchioles are to segmental bronchi
   b. alveoli are to alveolar ducts
   c. alveolar ducts are to respiratory bronchioles
   d. respiratory bronchioles are to alveolar ducts

Answer 0

d. respiratory bronchioles are to alveolar ducts

Question 1

2. The cilia of bronchial wall
   a. ingest bacteria
   b. trigger sneeze reflex
   c. trap & remove bacteria
   d. propel mucus & trapped bacteria toward the oropharynx

Answer 1

d. propel mucus & trapped bacteria toward the oropharynx

Question 2

3. As terminal bronchioles are approached
   a. the epithelium becomes thicker
   b. mucus-producing glands increase
   c. the epithelium becomes thinner
   d. cartilaginous support increases
   e. smooth muscle layer thickens

Answer 2

c. the epithelium becomes thinner

Question 3

4. The left bronchus
   a. is shorter & wider than right
   b. is symmetrical to right
   c. has a course that is more vertical than that of right
   d. is more angled than right
   e. has more bronchial wall layers than right

Answer 3

d. is more angled than right

Question 4

5. Respiratory unit consists of
   a. cilia
   b. bronchiolar arteries & veins
   c. goblet cells & aveoli
   d. respiratory bronchioles & alveoli

Answer 4

d. respiratory bronchioles & alveoli

Question 5

6. An increase of CO2 in arterial blood causes chemoreceptors to stimulate the respiratory centers to:
   a. decrease respiratory rate
   b. increase respiratory rate
   c. cause hypocapnia
   d. cause hypercapnia

Answer 5

b. increase respiratory rate

Question 6

7. Surfactant:
   a. facilitate O2 exchange
   b. produces nutrients for alveoli
   c. permits air exchange btw alveolar ducts
   d. facilitates alveolar expansion during expansion
   e. All of the above

Answer 6

d. facilitates alveolar expansion during expansion

Question 7

8. During expiration, which of the following relationship is TRUE?
   a. as lung volume decreases, number of molecules of gas increases
   b. as lung volume increases, number of molecules of gas increases
   c. as lung volume decreases, pressure increases
   d. as partial lung volume increases, less gas will dissolve in a liquid

Answer 7

c. as lung volume decreases, pressure increases

Question 8

9. When diaphragm & external intercostal contract:
   a. intrathoracic volume increases
   b. intrathoracic pressure increases
   c. intarthoracic volume decreases
   d. None of above is correct

Answer 8

a. intrathoracic volume increases

Question 9

10. O2 diffusion from alveolus to alveolar capillary occurs because
    a. PO2 is less in capillary than in alveolus
    b. PO2 is greater in atmosphere than in arterial blood
    c. O2 diffuses faster than CO2
    d. PO2 is higher in capillary than in alveolus

Answer 9

a. PO2 is less in capillary than in alveolus

Question 10

11. A shift to right in oxyhemoglobin dissociation curve
    a. prevents O2 release at cellular level
    b. causes O2 to bind tighter to Hgb
    c. improves O2 release at cellular level
    d. causes alkalosis

Answer 10

c. improves O2 release at cellular level

Question 11

12. In which sequence does PO2 progressively decrease?
    a. blood in aorta, atmospheric air, body tissues
    b. body tissues, arterial blood, alveolar air
    c. body tissues, alveolar air, arterial blood
    d. atmospheric air, blood in aorta, body tissues

Answer 11

d. atmospheric air, blood in aorta, body tissues

Question 12

13. Most O2 is carried in the blood ____, most CO2 is carried _____.
    a. dissolved in plasma, associated with salt/acid
    b. bound to hemoglobin, associated w/ bicarbonate/carbonic acid
    c. combined w/ albumin, associated w/ carbonic acid & Hgb
    d. bound to Hgb, bound to albumin

Answer 12

b. bound to hemoglobin, associated w/ bicarbonate/carbonic acid

Question 13

14. Alveoli are well suited for diffusion of respiratory gases b/c:
    a. they are small & thus have a small total surface area
    b. vascularization is minimal, thereby allowing greater air circulation
    c. they contain 4 thick layers, which prevent air leakage
    d. they contain surfactant, which helps prevent alveolar collapse

Answer 13

d. they contain surfactant, which helps prevent alveolar collapse

Question 14

15. Which ordinarily brings about greatest increase in rate of respiration?
    a. hypercapnia (excess CO2)
    b. increased O2
    c. increased arterial pH
    d. sudden rise in bp

Answer 14

a. hypercapnia (excess CO2)

Question 15

16. Given that O2 content of blood equals 1.34ml of O2 per gram of Hgb arterial O2 saturation percent, if Hgb concentration is 15g/dl & arterial saturation is 98%, what is arterial O2 content?
    a. 13.2 ml/dl of blood
    b. 19.7 ml/dl of blood
    c. 14.7 ml/dl of blood
    d. None of above

Answer 15

b. 19.7 ml/dl of blood

Question 16

17. Given that an individual has a RR of 15bpm & tidal volume of 500ml of air, the respiratory minute volume is:
    a. 7.5 L/min
    b. 75 L/min
    c. 750 L/min
    d. 7500 L/min

Answer 16

a. 7.5 L/min

Question 17

18. Stretch receptors:
    a. are sensitive to volume changes in the lung
    b. are located near capillaries in alveolar septa
    c. increase ventilatory rate when stimulated
    d. prevent lung underinflation when stimulated

Answer 17

a. are sensitive to volume changes in the lung

Question 18

19. Which of the following increases respiratory rate
    a. increased PCO2, decreased arterial pressure, decreased pH, decreased Po2
    b. increased PCO2, decreased arterial pressure, increased pH, decreased Po2
    c. decreased PCO2, decreased arterial pressure, decreased pH, increased Po2
    d. decreased PCO2, decreased arterial pressure, decreased pH, decreased Po2

Answer 18

a. increased PCO2, decreased arterial pressure, decreased pH, decreased Po2

Question 19

20. The dorsal respiratory group of neurons
    a. sets automatic rhythm of respiration
    b. modifies rhythm of respiration
    c. is active when increased ventilation is required
    d. None of the above

Answer 19

a. sets automatic rhythm of respiration

Question 20

21. Which of the following does NOT provide chemoreceptor input to medulla oblongata respiratory centers
    a. Medullary centers
    b. Olfactory epithelium
    c. Carotid artery
    d. Aortic body

Answer 20

b. Olfactory epithelium

Question 21

22. Parasympathetic stimulation to bronchiolar smooth muscle causes
    a. muscle relaxation
    b. increased tidal volume
    c. bronchodilation
    d. bronchoconstriction

Answer 21

d. bronchoconstriction

Question 22

23. The pons apneustic center
    a. inhibits inspiration
    b. stimulates/prolongs inspiration
    c. controls respiratory rhythm
    d. monitors blood gas tension

Answer 22

b. stimulates/prolongs inspiration

Question 23

24. During inhalation, the intrapleural pressure approximates:
    a. 1 mmHg
    b. 1 mmHg
    c. 6 mmHg
    d. 6 mmHg

Answer 23

c. 6 mmHg

Question 24

25. Control of airflow resistance & air distribution in lungs is controlled by
    a. trachea
    b. alveoli
    c. bronchioles
    d. diaphragm

Answer 24

c. bronchioles