Respiratory System
1. At which of the following locations is reduced hemoglobin converted to oxyhemoglobin?
Liver cells.
Heart ventricles.
Lung capillaries.
Tissue capillaries.
2. The medulla controls the breathing rate by monitoring the concentration of
oxygen.
carbon dioxide.
oxyhemoglobin.
carbaminohemoglobin.
3. The transport process by which gases enter and leave the blood during internal and external respiration is
osmosis.
diffusion.
active transport.
facilitated transport.
4. One reason that the pH of blood remains relatively constant during internal respiration is because
hydrogen ions form water.
hemoglobin transports hydrogen ions.
carbonic anhydrase forms hydrogen gas.
white blood cells absorb extra hydrogen.
5. The release of oxygen from hemoglobin is most closely associated with which of the following conditions?
Increased pH.
Decreased body temperature.
High amounts of oxygen in tissues.
Increased carbon dioxide concentration.
6. The process of inspiration is accomplished by
relaxation of the diaphragm.
reduced pressure in the chest cavity.
relaxation of the intercostal muscles.
increased pressure in the chest cavity.
7. The region of the respiratory and digestive tracts where both food and air passes is the
larynx.
trachea.
pharynx.
nasal sinus.
8. The breathing center is located in the
thalamus.
cerebrum.
hypothalamus.
medulla oblongata.
9. In which of the following locations does blood have the highest concentration of reduced hemoglobin?
Systemic veins.
Pulmonary veins.
Systemic arteries.
Pulmonary capillaries.
10. The exchange of carbon dioxide and oxygen between the air and the blood is called
breathing.
external respiration.
internal respiration.
cellular respiration.
11. Which of the following sequences correctly describes the passage of air out of the body?
Pharynx, larynx, trachea, bronchioles, alveoli, bronchi.
Pharynx, larynx, trachea, bronchi, bronchioles, alveoli.
Pharynx, trachea, bronchi, larynx, bronchioles, alveoli.
Alveoli, bronchioles, bronchi, trachea, larynx, pharynx.
12. A decrease in CO
2
in blood is most closely associated with
an decrease in blood pH.
contraction of the diaphragm.
an increase in plasma temperature.
increased bonding capacity of Hb for O
2
.
13. The pH of blood remains relatively constant during internal respiration because
CO
2
forms HCO
3
1-
.
of the activity of HCO
3
1-
.
HCO
3
1-
breaks down into H
2
O and CO
2
carbonic anhydrase forms hydrogen gas.
14. Which of the following initiates a nerve impulse from the lungs to the breathing center?
Lowering of the diaphragm.
Relaxation of the diaphragm.
Contraction of the rib muscles.
Increased volume of the alveoli.
15. Before reaching the lungs, the air that enters the respiratory tract during inspiration will normally be
cooled and dried out.
cooled and moistened.
warmed and dried out.
warmed and moistened.
16. As the plasma temperature decreases, the amount of CO
2
carried by hemoglobin will
decrease.
remain the same.
increase slightly.
become 99 to 100%.
17. Cells use oxygen during the process called
breathing.
external respiration.
internal respiration.
cellular respiration.
18. Receptors in the respiratory center of the brain are stimulated by
low oxygen levels.
high oxygen levels.
low carbon dioxide levels.
high carbon dioxide levels.
19. When compared to the blood in the regions where hemoglobin releases oxygen, the blood where oxygen bonds to hemoglobin to become oxyhemoglobin is relatively
acidic and cool.
acidic and warm.
basic (alkaline) and cool.
basic (alkaline) and warm.
20. The greatest production of bicarbonate ions occurs in the
aorta.
lung alveoli.
pulmonary vein.
systemic tissue capillaries.
21. A puncture or tear in the lining of the chest cavity would likely result in
collapse of both lungs.
decreased breathing rate and fainting.
collapse of the lung nearest the puncture/tear.
the leaking of gases (like oxygen) out of the chest cavity.
22. Oxygen passes into the blood capillaries through the walls of the
alveoli.
bronchioles.
pleural membranes.
pulmonary venules.
23. Which of the following correctly describes the muscle activity during exhalation?
Diaphragm relaxes; intercostal muscles relax.
Diaphragm contracts; intercostal muscles relax.
Diaphragm relaxes; intercostal muscles contract.
Diaphragm contracts; intercostal muscles contract.
24. In which form is most of the carbon dioxide transported in blood?
Dissolved gas.
Bicarbonate ions.
Reduced hemoglobin.
Carbaminohemoglobin.
25. The alveolar walls are moist so that
bacteria can be trapped.
water vapor can be inhaled.
water vapor can be exhaled.
gases can move freely through the membranes.