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18 Cards in this Set
- Front
- Back
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How does the respiratory system respond to exercise?
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1. Increased minute ventilation
2. Increased CO2 output 3. Increased O2 output 4. A-a gradient widens(excessive exercise) 5. Respiratory (CO2/O2) exchange ratio exceeds 1, but<1.25. |
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How does the amount of O2 in the body change with exercise?
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Increases because the quantity of O2 added to each unit of blood and the pulmonary blood flow per minute are increased.
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How does the Po2 of blood flowing into the pulmonary capillaries change with exercise?
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Falls to 25mm/Hg or less because of increased extraction.
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How does CO2 excretion change with exercise?
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Increased to as much as 40 fold because of increased amount of CO2 produced.
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What happens to the mean values for arterial PO2 and PCO2 during exercise?
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No change
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What happens to the level of lactate in the blood with exercise?
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It increases.
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Where does lactate come from?
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Muscles in which aerobic resynthesis of energy stores cannot keep pace with their utilization and an O2 debt is incurred.
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What happens to arterial pH during exercise?
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No change with moderate exercise, but it decreases with strenuous exercise due to lactic acidosis.
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What is hypoxia?
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O2 deficiency at the tissue level.
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What are the signs of hypoxia/
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Cyanosis, tachycardia and tachypnea.
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What are the symptoms of chronic hypoxia?
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Dyspnea and shortness of breath.
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Define dyspnea.
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Difficult or labored breathing in which the subject is conscious of shortness of breath.
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What causes cyanosis?
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Reduced hemoglobin, which has a dark color and causes a dusky bluish discoloration of the tissues.
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What physiologic changes occur at high altitudes?
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Alveolar PO2 decreases from decreased barometric pressure, which results in decreased arterial PO2(hypoxia)
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What is the acute response to high altitudes?
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Increased ventilatiopn rate(hyperventilation)
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What are the chronic responses to high altitudes?
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1. Increased ventilation rate
2. Increased erythropoietin production by kidneys, which increases Hb concentration 3. Increased 2, 3 DPG 4. Increased number of mitochondria in cells 5. Increased renal excretion of HCO3-. |
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What agent can be given to trat the respiratory alkalosis caused by the hyperventilation of hypoxia?
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Acetazolamide, which inhibits carbonic anhydrase resulting in increased urinary excretion of HCO3 and increased PaCO2.
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What is a consequence of chronic hypoxic pulmonary vasoconstriction?
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Right ventricular hypertrophy.
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