Lsn 16 HW 21.10-21.18

When the diaphragm and external intercostal muscles contract, the volume of the thorax increases. the volume of the thorax decreases. the volume of the lungs decreases. expiration occurs. the lungs shrink.

the volume of the thorax increases.

The partial pressure of oxygen in pulmonary veins during internal respiration is approximately 70 mm Hg. 40 mm Hg. 45 mm Hg. 95 mm Hg. 50 mm Hg.

95 mm Hg

The movement of chloride ions into the RBCs in exchange for bicarbonate ions is known as a bicarbonate exchange. the BPG pathway. gas diffusion. the Bohr effect. the chloride shift.

the chloride shift.

ost of the carbon dioxide in the blood is transported as solute dissolved in the plasma. carbonic acid. carbaminohemoglobin. bicarbonate ions. solute dissolved in the cytoplasm of red blood cells.

bicarbonate ions.

Each 100 mL of blood leaving the alveolar capillaries carries away roughly ________ of oxygen. 30 mL 75 mL 50 mL 20 mL 10 mL

20ml

Carbonic anhydrase is an enzyme. can convert carbon dioxide into carbonic acid. is in RBCs. can increase the amount of bicarbonate ion in plasma. All of the answers are correct.

All

Which statement regarding lung cancer is correct? About 40-55 percent of all lung cancers are the direct result of cigarette smoking. Lung cancers now account for 75 percent of new cancer cases in both men and women. Before about 1970, this disease primarily affected elderly women. Since 1992, the incidence of lung cancer among women has been increasing.

Since 1992, the incidence of lung cancer among women has been increasing.

If the dorsal respiratory group of neurons in the medulla oblongata were destroyed bilaterally, the respiratory minute volume would increase. alveolar ventilation would increase. pulmonary ventilation would increase markedly. tidal volumes would increase. a person would stop breathing.

a person would stop breathing.

Alveolar ventilation refers to the movement of dissolved gases from the blood to the alveoli. utilization of oxygen by alveolar cells to support metabolism. movement of air into and out of the lungs. movement of dissolved gases from the alveoli to the blood. amount of air reaching the alveoli each minute.

amount of air reaching the alveoli each minute.

Air remaining in the conducting portion of the respiratory system that does not reach the alveoli is known as minimal volume. alveolar ventilation volume. respiratory minute volume. functional residual capacity. anatomic dead space.

anatomic dead space.

A period in which breathing has stopped, followed by a forceful expulsion of air is termed apnea. apneustic breathing. anoxia. hypoxia. respiratory distress.

apnea.

Prolonged deep inspirations can result from stimulating the ________ center. chemoreceptor baroreceptor pneumotaxic apneustic expiratory

apneustic

The most important chemical regulator of respiration is oxygen. hemoglobin. carbon dioxide. bicarbonate ion. sodium ion.

carbon dioxide.

Which of the following factors would increase the amount of oxygen discharged by hemoglobin to peripheral tissues? decreased pH decreased amounts of BPG decreased temperature increased tissue PO2 None of the answers is correct.

decreased pH

The obstructive lung disease in which elastic fibers are lost, leading to collapse of alveoli and bronchioles, is called emphysema. tuberculosis. bronchitis. pneumonia. asthma.

emphysema

Dalton's law states that the volume of gas that will dissolve in a solvent is proportional to the solubility of the gas and the gas pressure. in a mixture of gases such as air, the total pressure is the sum of the individual partial pressures of the gases in the mixture. gas volume and temperature are directly proportional. gas pressure is inversely proportional to gas volume. gas volume and pressure are inversely proportional.

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

In quiet breathing, inspiration and expiration involve muscular contractions. inspiration involves muscular contractions and expiration is passive. inspiration and expiration are both passive. inspiration is passive and expiration involves muscular contractions. None of the answers is correct.

inspiration involves muscular contractions and expiration is passive.

At a PO2 of 70 mm Hg and normal temperature and pH, hemoglobin is ________ percent saturated with oxygen. more than 90 75 25 10 50

more than 90

Emphysema: is a long-term inflammation and swelling of the bronchial lining. occurs due to the destruction of alveolar surfaces and inadequate surface area for oxygen and carbon dioxide exchange. occurs in individuals identified as blue bloaters. is a condition characterized by conducting passageways that are extremely sensitive to irritants.

occurs due to the destruction of alveolar surfaces and inadequate surface area for oxygen and carbon dioxide exchange.

Which of the following can be calculated if the tidal volume and respiratory rate are known? expiratory reserve volume respiratory minute volume anatomic dead space minimal volume inspiratory reserve volume

respiratory minute volume