BMS 420 TEST 4 QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026

BMS 420 TEST 4 QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026 Voluntary apnea (i.e. breath-holding) for 2 minutes would a) Decrease PaO2 b) All of the above c) Stimulate the central chemoreceptors d) Increase PaCO2 e) Stimulate the peripheral chemoreceptors - Answers b) All of the above All of the following conditions would be expected to stimulate the peripheral chemoreceptors except a) Mild anemia b) Hypoxia due to ascent to high altitude c) Acute airway obstruction d) Strenuous exercise - Answers a) Mild anemia Stimulation of which of the following receptors should result in decreased ventilation? a) Peripheral chemoreceptors b) Central chemoreceptors c) Pulmonary stretch receptors - Answers c) Pulmonary stretch receptors The respiratory control center responsible for the generation of the respiratory pattern is the a) Pons b) Pre-Botzinger Complex c) Dorsal Respiratory Group d) Ventral Respiratory Group - Answers b) Pre-Botzinger Complex These chemoreceptors do not respond to changes in PaO2. a) Aortic chemoreceptors b) Carotid chemoreceptors c) Central chemoreceptors - Answers c) Central chemoreceptors During acute alveolar hyperventilation, the blood a) pH decreases b) PCO2 increases c) Bicarbonate (HCO3-) increases d) Carbonic acid (H2CO3) decreases - Answers d) Carbonic acid (H2CO3) decreases The buffering capacity of cerebral spinal fluid is lower than that of the plasma due to a) A lower protein concentration b) A lower H+ concentration c) A higher concentration of bicarbonate ion - Answers a) A lower protein concentration A decrease in the PO2 of inspired air will lead to a) A decrease in the cerebral spinal fluid H+ concentration b) An increase in PaCO2 c) Inhibition of the peripheral chemoreceptors d) An increase in PAO2 - Answers a) A decrease in the cerebral spinal fluid H+ concentration The increase in ventilation in response to low PaO2 is known as a) The Hypoxic Ventilatory Response b) Hypoxic Pulmonary Vasoconstriction c) Alveolar dead space d) A pulmonary shunt - Answers a) The Hypoxic Ventilatory Response Shallow water blackout can occur a) towards the end of a breath-hold dive that was preceded by hyperventilation b) immediately on descent during a breath-hold dive following hyperventilation c) any time during breath-holding - Answers a) towards the end of a breath-hold dive that was preceded by hyperventilation Which Gas Law influences the on-set of oxygen toxicity? a) Henry's Law b) Boyle's Law c) Fick's Law - Answers a) Henry's Law why is the PAO2 lower at the surface at the end of the dive compared to at the beginning? (choose all correct answers) a) Lung expansion during ascent b) O2 consumption during the dive C) Loss of O2 due to hyperventilation - Answers a) Lung expansion during ascent and b) O2 consumption during the dive Nitrogen narcosis leads to an impairment of mental processes and neuromuscular coordination due to a) displacement of O2 from the blood as a result of an increase in N2 pressure b) the anesthetic effect that high N2 pressures have on nerve transmission c) competitive binding of N2 to hemoglobin that can occur at high pressures - Answers b) the anesthetic effect that high N2 pressures have on nerve transmission Oxygen toxicity is unlikely to occur at higher altitudes while breathing high percentages of oxygen a) Oxygen toxicity is just as likely to occur at higher altitudes as it is sea level when breathing high percentages of oxygen b) due to the suppression of the hypoxic ventilatory response c) because the PaO2 is lower at altitude compared to the PaO2 that would result from breathing the same percentage oxygen at sea level d) only if alveolar ventilation is reduced, resulting in a decrease in the amount of oxygen that participates in gas exchange - Answers c) because the PaO2 is lower at altitude compared to the PaO2 that would result from breathing the same percentage oxygen at sea level The risk of pulmonary barotrauma is______ during ascent from compressed air diving than breath-hold diving due to ______ a) the same; the lungs of both divers returning to their original volume upon reaching the surface, even if the compressed air diver holds their breath b) greater; the diver breathing compressed air at depth has not depleted the oxygen in the lungs, resulting in greater expansion of the lungs even while breathing normally c) greater; the potential of lung over inflation if a diver holds their breath that results from expansion of the compressed gas inhaled at depth d) less; the fact that the breath-hold diver has depleted the oxygen in the lungs, resulting in less expansion of the lungs even while breathing normally - Answers c) greater; the potential of lung over inflation if a diver holds their breath that results from expansion of the compressed gas inhaled at depth Which of the following will result in an increase in alveolar ventilation? a) Decreased PvCO2 b) Increased PaCO2 c) Increased pH d) Increased PvCO2 - Answers b) Increased PaCO2 High PaO2 values do not increase alveolar ventilation because a) At PaO2 values greater than approximately 60 mmHg, a sufficient number of the oxygen binding sites on hemoglobin are filled, meaning that there is sufficient oxygen delivery to meet metabolic demands