respiratory half part /(exam 3)

Select the correct statement about oxygen transport in blood: During conditions of acidosis, hemoglobin is able to carry oxygen more efficiently. A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal. During normal activity, a molecule of hemoglobin returning to the lungs carries one molecule of O2. Increased BPG levels in the red blood cells enhance oxygen-carrying capacity.

A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal.

The partial pressure of oxygen in the interstitial space of peripheral tissues is approximately A) 40 mm Hg. B) 70 mm Hg. C) 100 mm Hg. D) 45 mm Hg. E) 50 mm Hg.

A) 40 mm Hg.

When does oxyhemoglobin form during respiration? A) during external respiration B) immediately after carbon dioxide enters the blood C) when the chloride shift occurs D) during internal respiration E) during pulmonary ventilation

A) during external respiration

The partial pressure of carbon dioxide in the interstitial space of peripheral tissues is approximately A) 35 mm Hg. B) 45 mm Hg. C) 55 mm Hg. D) 100 mm Hg. E) 70 mm Hg.

B) 45 mm Hg.

As an astronaut is lifted into Earth's orbit, what is the first change to take place in response to the drop in cabin pressure? A) increased hematocrit B) decreased alveolar PO2 C) renal hypoxia D) increased alveolar ventilation rate E) decreased hemoglobin saturation

B) decreased alveolar PO2

The percent of oxygen saturation of hemoglobin when the pH is 7.6 is A) less than the percent of oxygen saturation of hemoglobin when the pH is 7.2. B) greater than the percent of oxygen saturation of hemoglobin when the pH is 7.2. C) equal to the percent of oxygen saturation of hemoglobin when the pH is 7.2.

B) greater than the percent of oxygen saturation of hemoglobin when the pH is 7.2

The percent of oxygen saturation of hemoglobin when the temperature is 38 degrees centigrade is A) equal to the percent of oxygen saturation of hemoglobin when the temperature is 43 degrees centigrade. B) greater than the percent of oxygen saturation of hemoglobin when the temperature is 43 degrees centigrade. C) less than the percent of oxygen saturation of hemoglobin when the temperature is 43 degrees centigrade.

B) greater than the percent of oxygen saturation of hemoglobin when the temperature is 43 degrees centigrade.

Hemoglobin's affinity for oxygen when the BPG level is high is A) equal to hemoglobin's affinity for oxygen when the BPG level is low. B) less than hemoglobin's affinity for oxygen when the BPG level is low. C) greater than hemoglobin's affinity for oxygen when the BPG level is low.

B) less than hemoglobin's affinity for oxygen when the BPG level is low

Carbonic anhydrase A) can decrease the amount of bicarbonate ion in plasma. B) is an enzyme. C) is in RBCs. D) can increase the amount of bicarbonate ion in plasma. E) All of the answers are correct.

E) all of the answers are correct

Carbon dioxide and water combine to form A) carbaminohemoglobin. B) nitric acid. C) oxygen. D) hydrochloric acid. E) carbonic acid.

E) carbonic acid.

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

E) more than 90

Determination of blood gases includes testing an arterial sample for A) pH. B) PCO2. C) PO2. D) PO2 and PCO2 only. E) pH, PO2, and PCO2.

E) pH, PO2, and PCO2.

Blockage of pulmonary blood flow by a clot or similar obstruction is A) pneumothorax. B) anoxia. C) COPD. D) emphysema. E) pulmonary embolism.

E) pulmonary embolism.

Increased temperature results in decreased O2 unloading from hemoglobin.

False

Oxygenated hemoglobin releases oxygen more readily when the pH is more basic.

False

The Hering-Breuer reflex is a potentially dangerous response that may cause overinflation of the lung.

False

The largest amount of carbon dioxide is transported in the bloodstream in the form of carbonic anhydrase.

False

Which of the following is correct regarding acclimatization? When blood O2 levels decline, the kidneys produce more erythropoietin, which stimulates breakdown of red blood cells in the spleen. High-altitude conditions always result in lower-than-normal hemoglobin saturation levels because less O2 is available to be loaded. At high altitudes, hemoglobin's affinity for O2 is increased because BPG concentrations increase. Decreases in arterial PO2 cause the peripheral chemoreceptors to become less responsive to increases in PCO2.

High-altitude conditions always result in lower-than-normal hemoglobin saturation levels because less O2 is available to be loaded.

Ventilation perfusion coupling means that more blood flows past functional alveoli than past nonfunctional alveoli.

True

A premature baby usually has difficulty breathing. However, the respiratory system is developed enough for survival by ________. a. 24 weeks b. 28 weeks c. 17 weeks d. 36 weeks

b. 28 weeks

Surfactant helps to prevent the alveoli from collapsing by ________.

interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid

Surfactant helps to prevent the alveoli from collapsing by ________. warming the air before it enters interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid protecting the surface of alveoli from dehydration and other environmental variations humidifying the air before it enters

interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid

The major nonelastic source of resistance to air flow in the respiratory passageways is ________. surfactant surface tension friction air pressure

friction

Which center is located in the pons? expiratory inspiratory pacemaker neuron center pontine respirator group (PRG)

pontine respirator group (PRG)

The symptoms of hyperventilation may be averted by breathing into a paper bag because it ________. helps retain carbon dioxide in the blood lowers blood pH levels reduces brain perfusion by constricting cerebral blood vessels helps retain oxygen in the blood

helps retain carbon dioxide in the blood

The most powerful respiratory stimulus for breathing in a healthy person is ________. increase of carbon dioxide pH (alkalosis) pH (acidosis) loss of oxygen in tissues

increase of carbon dioxide

Which of the following is not a stimulus for breathing? rising carbon dioxide levels arterial Po2 below 60 mm Hg rising blood pressure arterial pH resulting from CO2 retention

rising blood pressure

Which of the following is a conducting zone structure? alveolar duct alveolar sac terminal bronchiole respiratory bronchiole

terminal bronchiole

Which of the choices below describes the forces that act to pull the lungs away from the thorax wall and thus collapse the lungs? the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid compliance and transpulmonary pressures compliance and the surface tension of the alveolar fluid the natural tendency for the lungs to recoil and transpulmonary pressures

the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid

Factors that influence the rate and depth of breathing include ________. stretch receptors in the alveoli voluntary cortical control thalamic control composition of alveolar air

voluntary cortical control

A 10-percent increase in the level of carbon dioxide in the blood will A) increase the rate of breathing. B) decrease pulmonary ventilation. C) decrease the alveolar ventilation rate. D) decrease the rate of breathing. E) decrease the vital capacity.

A) increase the rate of breathing.

Decompression sickness is a painful condition that develops when a person is exposed to a sudden drop in atmospheric pressure. Bubbles of ________ gas are responsible for the problem. A) nitrogen B) carbon monoxide C) oxygen D) helium E) carbon dioxide

A) nitrogen

For maximum loading of hemoglobin with oxygen at the lungs, the A) DPG levels in the red blood cells should be high. B) PCO2 should be high. C) PCO2 should be low. D) pH should be slightly acidic. E) PO2 should be about 70 mm Hg.

C) PCO2 should be low.

The term hypercapnia refers to A) the cessation of breathing. B) labored breathing. C) elevated PCO2. D) elevated PO2. E) an increase in pH.

C) elevated PCO2.

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

C) emphysema.

About 70% of carbon dioxide is transported in deoxygenated blood A) as carbonic acid in the red blood cells. B) as dissolved CO2 in the blood plasma. C) as bicarbonate ions bound to hemoglobin in red blood cells. D) as bicarbonate ions in the blood plasma. E) combined with hemoglobin as carbaminohemoglobin.

D) as bicarbonate ions in the blood plasma.

Low pH alters hemoglobin structure so that oxygen binds less strongly to hemoglobin at low PO2. This increases the effectiveness of A) external respiration. B) hemoglobin synthesis. C) acid-base balance. D) internal respiration. E) carbon dioxide transport.

D) internal respiration

A pulmonary embolism can be caused by ________ becoming trapped in a pulmonary artery. A) blood clots B) air bubbles C) circulating objects in the blood D) masses of fat E) All of the answers are correct.

E) All of the answers are correct.

Carbonic anhydrase A) can decrease the amount of bicarbonate ion in plasma. B) is an enzyme. C) is in RBCs. D) can increase the amount of bicarbonate ion in plasma. E) All of the answers are correct.

E) All of the answers are correct.

Which statement about CO2 is incorrect? More CO2 dissolves in the blood plasma than is carried in the RBCs. Its accumulation in the blood is associated with a decrease in pH. CO2 concentrations are greater in venous blood than arterial blood. Its concentration in the blood is decreased by hyperventilation.

More CO2 dissolves in the blood plasma than is carried in the RBCs.

Select the correct statement about the physical factors influencing pulmonary ventilation. a. As alveolar surface tension increases, additional muscle action will be required. b. Surfactant helps increase alveolar surface tension. c. A decrease in compliance causes an increase in ventilation. d. A lung that is less elastic will require less muscle action to perform adequate ventilation.

a. As alveolar surface tension increases, additional muscle action will be required.

Which of the following determines lung compliance? a. alveolar surface tension b. airway opening c. muscles of inspiration d. flexibility of the thoracic cage

a. alveolar surface tension

With the Bohr effect, more oxygen is released because a(n) ________. a. decrease in pH (acidosis) weakens the hemoglobin-oxygen bond b. decrease in pH (acidosis) strengthens the hemoglobin-oxygen bond c. increase in pH (alkalosis) weakens the hemoglobin-oxygen bond d. increase in pH (alkalosis) strengthens the hemoglobin-oxygen bond

a. decrease in pH (acidosis) weakens the hemoglobin-oxygen bond

What occurs if intrapulmonic pressure is 763 mm Hg? a. exhalation b. apnea c. hyperventilation d. inhalation e. pause in breathing

a. exhalation

The partial pressure of carbon dioxide is greatest in a. venous blood b. arterial blood c. inspired air d. alveolar air e. expired air

a. venous blood

Which of the following provide the greatest surface area for gas exchange? respiratory bronchioles alveolar sacs alveoli alveolar ducts

alveoli

How is the bulk of carbon dioxide carried in blood? chemically combined with the heme portion of hemoglobin chemically combined with the amino acids of hemoglobin as carbaminohemoglobin in the red blood cells as the bicarbonate ion in the plasma after first entering the red blood cells as carbonic acid in the plasma

as the bicarbonate ion in the plasma after first entering the red blood cells

How is the bulk of carbon dioxide carried in blood? chemically combined with the heme portion of hemoglobin chemically combined with the amino acids of hemoglobin as carbaminohemoglobin in the red blood cells as the bicarbonate ion in the plasma after first entering the red blood cells as carbonic acid in the plasma GOES WITH as the bicarbonate ion in the plasma after first entering the red blood cells

as the bicarbonate ion in the plasma after first entering the red blood cells

Which of the following correctly describes mechanisms of CO2 transport? as bicarbonate ion in plasma attached to the heme part of hemoglobin 7 10% of CO2 is dissolved directly into the plasma 20% of CO2 is carried in the form of carbaminohemoglobin

attached to the heme part of hemoglobin

Because the lungs are filled with fluid during fetal life, which of the following statements is true regarding respiratory exchange? a. Respiratory exchanges are made through the ductus arteriosus. b. Respiratory exchanges are made through the placenta. c. Because the lungs develop later in gestation, fetuses do not need a mechanism for respiratory exchange. d. Respiratory exchanges are not necessary.

b. Respiratory exchanges are made through the placenta.

Most of the carbon dioxide in the blood is transported as a. carbonic acid b. bicarbonate ions c. solute dissolved in the plasma d. solute dissolved in the cytoplasm of red blood cells e. carbaminohemoglobin

b. bicarbonate ions

When each hemoglobin molecule binds with four molecules of oxygen, the end product is __________. a. carbon monoxide b. oxyhemoglobin c. carbaminohemoglobin d. carbon dioxide

b. oxyhemoglobin

Which of the following statements about the chloride shift is false? a. It involves a movement of chloride ion into RBCs b. It depends on the chloride-bicarbonate countertransporter c. It causes RBCs to swell d. It is driven by a rise in PCO2 e. It involves a movement of bicarbonate ions into the plasma

c. It causes RBCs to swell

In the pulmonary capillaries, the bicarbonate ion is always returned to the __________. a. interstitial fluid b. plasma c. RBC d. alveoli

c. RBC

Carbon dioxide is transported in the blood mostly as __________. a. soluble in plasma b. carbaminohemoglobin c. a bicarbonate ion d. none of the listed responses

c. a bicarbonate ion

temperature is lower at higher altitudes concentration of oxygen and/or total atmospheric pressure is lower at high altitudes basal metabolic rate is higher at high altitudes concentration of oxygen and/or total atmospheric pressure is higher at higher altitudes

concentration of oxygen and/or total atmospheric pressure is lower at high altitudes

When levels of CO2 rise in the blood, which of the following changes will occur? a. Hemoglobin releases O2. b. Levels of HCO3- increase. c. pH levels decrease. d. All of the above changes will occur with an increase in CO2

d. All of the above changes will occur with an increase in CO2

Which of the following factors would increase the amount of oxygen discharged by hemoglobin to peripheral tissues? a. decreased amounts of BPG b. decreased temperature and c. decreased amounts of BPG d. decreased temperature c. increased tissue PO2 d. decreased pH

d. decreased pH

The chloride shift occurs in order to a. pump hydrochloric acid out of gastric cells b. force oxygen out of the blood and into tissues c. produce salt for the cytosol of blood cells d. transport bicarbonate ions into the blood plasma e. produce carbonic acid

d. transport bicarbonate ions into the blood plasma

With the Bohr effect, more oxygen is released because a(n) ________. increase in pH (alkalosis) strengthens the hemoglobin-oxygen bond decrease in pH (acidosis) strengthens the hemoglobin-oxygen bond decrease in pH (acidosis) weakens the hemoglobin-oxygen bond increase in pH (alkalosis) weakens the hemoglobin-oxygen bond

decrease in pH (acidosis) weakens the hemoglobin-oxygen bond

As carbon dioxide enters systemic blood, it causes more oxygen to dissociate from hemoglobin (the Haldane effect), which in turn allows more CO2 to combine with hemoglobin and more bicarbonate ion to be generated (the Bohr effect).

false

Which of the following does not influence hemoglobin saturation? a. temperature b. DPG c. nitric oxide d. carbon dioxide

nitric oxide

Which of the choices below is not a factor that promotes oxygen binding to and dissociation from hemoglobin? number of red blood cells partial pressure of oxygen partial pressure of carbon dioxide

number of red blood cells

In the plasma, the quantity of oxygen in solution is ________. greater than the oxygen combined with hemoglobin only about 1.5% of the oxygen carried in dissolved form not present except where it is combined with carrier molecules about equal to the oxygen combined with hemoglobin

only about 1.5% of the oxygen carried in dissolved form

The Bohr effect refers to the unloading of ________ in a RBC due to declining blood pH. BPG chloride ions oxygen carbon dioxide

oxygen

Unlike inspiration, expiration is a passive act because no muscular contractions are involved. Expiration, however, depends on two factors. Which of the choices below lists those two factors? combined amount of CO2 in the blood and air in the alveoli the expansion of respiratory muscles that were contracted during inspiration and the lack of surface tension on the alveolar wall the negative feedback of expansion fibers used during inspiration and the outward pull of surface tension due to surfactant the recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid

the recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid

Atelectasis (lung collapse) renders the lung useless for ventilation.

true

Labored breathing is termed dyspnea.

true

Smoking diminishes ciliary action and eventually destroys the cilia.

true