Q&A Hero

Q: During exercise, arterial carbon dioxide is normally increased.

Q: Which of the following changes would occur during exercise? A. increased blood gases B. decreased ventilation C. decreased oxygen delivery to muscles D. increased oxygen extraction by muscles

Q: The immediate increase in ventilation as exercise begins can be explained through both neurogenic and humoral responses.

Q: Blood pH decreases over time during moderate to heavy exercise.

Q: An increase in ventilation due to a higher elevation is called A. hypoxic ventilatory response. B. acute mountain sickness. C. thalassemia. D. Bohr effect.

Q: Acclimatization to altitude results in increased oxygen loading.

Q: Acclimatization to high altitude results in __________ 2,3-DPG in erythrocytes. increased B. decreased C. no change in Chapter 16

Q: Acclimatization to altitude A. stimulates increased blood cell synthesis. B. decreases ventilation. C. increases the affinity of hemoglobin for oxygen. D. All of the choices are correct.

Q: Nitric oxide (NO) may form the following compound and increase the drive to breath. A. NO2 B. HCO3 C. SNOs D. SIDS

Q: Carbon dioxide _____ oxygen unloading and oxygen unloading _______ carbon dioxide transport. A. increases, improves B. increases, worsens C. decreases, improves D. decreases, worsens

Q: The chloride shift and its reverse play an important role in the acid-base balance of the blood.

Q: Where does the reverse chloride shift occur? A. tissue capillaries B. pulmonary capillaries C. arterioles D. venules

Q: Respiratory acidosis results from hyperventilation.

Q: Hypoventilation can correct A. metabolic acidosis. B. respiratory acidosis. C. metabolic alkalosis. D. respiratory alkalosis.

Q: The affinity of hemoglobin for oxygen A. is greater than the affinity for carbon monoxide. B. is increased in methemoglobin. C. decreases as the height above sea level increases. D. is increased in response to metabolic alkalosis.

Q: The metabolic regulation of blood pH occurs in A. the lungs. B. the liver. C. the kidneys. D. all organs.

Q: Carbonic acid is a volatile acid since its concentration in the blood is controlled by breathing.

Q: Metabolic alkalosis A. may be caused by excessive vomiting. B. occurs when the partial pressure of oxygen is decreased. C. occurs when arterial pH is less than 7.4. D. is induced by hypoventilation.

Q: A pH above 7.45 is considered A. acidosis. B. alkalosis. C. normal. D. metabolic.

Q: The highest oxygen affinity is demonstrated by A. hemoglobin A. B. hemoglobin F. C. myoglobin. D. hemoglobin S.

Q: Myoglobin has a greater affinity for oxygen than hemoglobin.

Q: Inhibiting carbonic anhydrase in erythrocytes would cause a decrease in the pH of arterial blood.

Q: The exchange of chloride ions for bicarbonate through tissue capillaries is called the A. chloride shift. B. Bohr effect. C. oxygen toxicity. D. acidosis.

Q: The majority of carbon dioxide is transported in the blood as A. dissolved carbon dioxide in the blood. B. bicarbonate ion. C. carbaminohemoglobin. D. carboxyhemoglobin.

Q: The enzyme ______ catalyzes the formation of H2CO3 from CO2 and water. A. renin B. nitric oxide synthase C. lactate dehydrogenase D. carbonic anhydrase

Q: Which of the following will decrease the affinity of hemoglobin for oxygen? A. decreased pH, decreased temperature, or decreased 2,3-DPG B. decreased pH, increased temperature, or increased 2,3-DPG C. increased pH, increased temperature, or decreased 2,3-DPG D. increased pH, decreased temperature, or increased 2,3-DPG

Q: A family of hemoglobin diseases found primarily in people of Mediterranean ancestry is A. thalassemia. B. sickle-cell anemia. C. myoglobinemia. D. leukemia.

Q: Persons with thalassemia will have large amounts of hemoglobin F.

Q: What disease is characterized by the abnormal hemoglobin S? A. sickle-cell anemia B. thalassemia C. cystic fibrosis D. emphysema

Q: Sickle-cell anemia can be treated with the drug hydroxyurea which stimulates A. production of hemoglobin gamma chains. B. destruction of hemoglobin beta chains. C. production of hemoglobin alpha chains. D. destruction of hemoglobin S.

Q: Myoglobin binds to more oxygen molecules than hemoglobin.

Q: According to the Bohr effect, as pH is lowered, the affinity of hemoglobin for oxygen A. increases. B. decreases. C. remains unchanged.

Q: Tissues receive more O2 when the pH is lowered.

Q: When tissues are producing more CO2 through increased metabolic activity, less O2 is provided to those tissues.

Q: A decrease in temperature will shift the oxygen dissociation curve to the A. right. left. C. will not shift the curve. Chapter 16

Q: An increase in 2,3-diphosphoglyceric acid (2,3-DPG) will ________ the affinity of hemoglobin for oxygen. A. increase decrease C. have no effect on Chapter 16

Q: What type of hemoglobin cannot bind to 2,3-DPG and thus has a higher affinity for oxygen? A. hemoglobin F B. hemoglobin A C. hemoglobin B D. hemoglobin G

Q: Hemoglobin F A. has a lower affinity for oxygen than hemoglobin A. B. contains two alpha and two gamma chains. C. binds large amounts of 2,3-DPG. D. is increased in sickle-cell anemia.

Q: 2,3-DPG comes from A. aerobic respiration in red blood cells. B. anaerobic respiration in red blood cells. C. type II alveolar cells. D. tissues with high amounts of oxygen.

Q: In anemia, 2,3-DPG is ________ and oxygen affinity is ________. A. decreased, decreased. B. decreased, increased. C. increased, increased. D. increased, decreased.

Q: A decreased affinity for oxygen shifts the oxygen dissociation curve to the right.

Q: The form of hemoglobin with iron in an oxidized state is A. oxyhemoglobin. B. deoxyhemoglobin. C. methemoglobin. D. carboxyhemoglobin.

Q: The form of hemoglobin with iron in a reduced state and bonded to oxygen is A. oxyhemoglobin. B. deoxyhemoglobin. C. methemoglobin. D. carboxyhemoglobin.

Q: The form of hemoglobin with iron in a reduced state and not bonded to oxygen is A. oxyhemoglobin. B. deoxyhemoglobin. C. methemoglobin. D. carboxyhemoglobin.

Q: The form of hemoglobin with iron in a reduced state and bonded to carbon monoxide is A. oxyhemoglobin. B. deoxyhemoglobin. C. methemoglobin. D. carboxyhemoglobin.

Q: Carbon monoxide is lethal because it A. reduces CO2 and slows breathing. B. increases CO2 and causes seizures. C. binds hemoglobin preventing oxygen binding. D. increases oxygen unloading at the cells.

Q: The formation of oxyhemoglobin from deoxyhemoglobin at the lungs is called an unloading reaction.

Q: The affinity of hemoglobin for oxygen is __________ as the partial pressure of oxygen is raised. A. increased B. decreased C. unchanged

Q: What is the normal value of arterial percent hemoglobin saturation? A. 100% B. 97% C. 90% D. 86%

Q: Increasing arterial blood temperature decreases the affinity of hemoglobin for oxygen.

Q: The Bohr effect A. describes the effect of pH on the affinity of hemoglobin for oxygen. B. describes the effect of pH on the affinity of hemoglobin for carbon dioxide. C. describes the mechanism of ventilation. D. describes the effect of solubility on the amount of gas dissolved in blood.

Q: Arterial percent oxygen saturation is greatly affected by exercise.

Q: At rest, normal oxygen unloading is ____. A. 97% B. 75% C. 39% D. 22%

Q: The production of hemoglobin and red blood cells in bone marrow is controlled by a hormone called thymopoietin.

Q: __________ is characterized by high red blood cell counts. A. Anemia B. Polycythemia C. Uremia D. Leukemia

Q: Renal production of __________ is stimulated by hypoxemia. A. renin B. colony-stimulating factor C. erythropoietin D. thrombopoietin

Q: If PO2 and hemoglobin content of blood is normal, how much oxygen is the blood carrying? A. 0.3 mL O2/ 100 mL blood B. 10 mL O2/ 100 mL blood C. 20 mL O2/ 100 mL blood D. 35 mL O2/ 100 mL blood

Q: Hyperventilation is stimulated by A. increased activity of the apneustic center. B. decreased contraction of the scalenes. C. hypercapnia D. hypoxemia.

Q: What type of receptors in the wall of the larynx, along with rapidly adapting receptors in the lungs, cause a person to cough in response to components of smoke and smog? A. aortic bodies B. pulmonary stretch receptors C. medullary chemoreceptors D. irritant receptors

Q: What type of nerve fibers are stimulated by capsaicin that causes apnea, then rapid, shallow breathing? A. myelinated A fibers B. unmyelinated C fibers C. unmyelinated B fibers D. myelinated C fibers

Q: Limits on stretching the lungs are due to the A. Haldane effect. B. law of Laplace. C. Hering-Breuer reflex. D. None of the choices is correct.

Q: Arterial blood pH is indirectly proportional to the partial carbon dioxide pressure of arterial blood.

Q: Central chemoreceptors respond to changes in arterial oxygen and carbon dioxide.

Q: Hypocapnia would induce a rise in the pH of arterial blood.

Q: Peripheral chemoreceptors that can detect changes in blood pH are located in the A. medulla oblongata. B. aortic and carotid bodies. C. pons. D. lungs.

Q: Peripheral chemoreceptors are directly stimulated by blood CO2 levels.

Q: Central chemoreceptors in the medulla oblongata directly detect changes in the pH of the A. blood. B. cerebrospinal fluid. C. lymph. D. air.

Q: The primary drive to breath is elicited by which of the following: A. reduced PO2. B. reduced PCO2. C. increased PO2. D. increased PCO2.

Q: What is the condition of having low blood oxygen levels? A. hypocapnia B. hypercapnia C. hypoxia D. hypoxemia

Q: The direct role of blood oxygen levels in controlling respiration is called A. hypoxic drive. B. hypocapnia. C. oxygen perfusion. D. acidosis.

Q: The rhythmicity center is located in the A. pons. B. cerebral cortex. C. medulla oblongata. D. midbrain.

Q: The dorsal respiratory group in the medulla oblongata is involved with A. inspiration. B. expiration. C. breathing rhythm. D. both inspiration and expiration.

Q: The I neurons of the dorsal respiratory group stimulate the A. sympathetic nervous system. B. phrenic nerve. C. vagus nerve. D. parasympathetic nervous system.

Q: Pulmonary arterioles _____ and system arterioles _____ when PO2 is low. A. dilate, dilate B. dilate, constrict C. constrict, dilate D. constrict, constrict

Q: When alveolar ventilation increases, the perfusion of pulmonary arterioles will A. increase. B. decrease. C. remain unchanged.

Q: What condition is caused by large amounts of nitrogen dissolving into the blood due to hyperbaric conditions? A. nitrogen narcosis B. oxygen toxicity C. decompression sickness D. emphysema

Q: What can be used to treat carbon monoxide poisoning and gangrene? A. hypoventilation B. blood letting C. hyperbaric oxygen therapy D. carbon dioxide therapy

Q: Hyperbaric oxygen therapy A. is used to treat nitrogen narcosis. B. exposes patients to high oxygen under low pressure. C. can be used to promote wound healing. D. would increase the time required to recover from decompression sickness.

Q: When a diver descends 20 meters below sea level, the total atmospheric pressure would be _______ the pressure at sea level. A. double B. triple C. quadruple D. the same as

Q: Decompression sickness is caused by ascending to sea level too quickly which results in bubbles of _____ to form in the blood. A. oxygen B. carbon dioxide C. carbon monoxide D. nitrogen