Biol 105 - heart and lung

Choose the correct answer for each question.

1 Which of the following is not a hallmark of increased aerobic fitness? Increased maximum oxygen uptake during exercise. Increased maximum cardiac output during exercise. Increased amount of oxygen extracted per unit blood during exercise. Increased amount of venous oxygen. All of the above are hallmarks of increased aerobic fitness 2 Suppose the windows of a 737 blow out at 20,000 ft reducing cabin oxygen levels. Which of the following responses will help maintain tissue oxygen levels in the cabin passengers during the 20 minutes before the plane lands? Increase in red blood cell mass. About 65% increase in the ventilatory rate 300-700% increase in the ventilatory rate Increased capillarity in the skeletal muscles None of the above. 3 Suppose you are trekking from Kathmandu to the Everest Base Camp. Which of the following describes most accurately a response that will help maintain tissue oxygen levels by the time you have reached base camp (let's say about 1 month from the start of your trek). Decrease in arterial blood pressure. About 65% increase in the ventilatory rate. Increase in red blood cell mass. Decreased brain blood flow None of the above. 4 Movement of air into the lung alveoli from the external atmosphere Is a convective process Occurs because external atmospheric pressure is less than alveolar pressure Requires oxygen to bind to hemoglobin Depends on the partial pressure of carbon dioxide None of the above. 5 Partial pressure of oxygen in an alveolus Is usually about 100 mmHg Increases when ventilatory rate is increased Increases when diffusion into the blood is increased A and B All of the above. 6 Which of the following would increase the rate of diffusion of oxygen from the alveolus into the blood? Reduction in venous oxygen partial pressure Reduction in alveolar oxygen partial pressure Increase in the diffusion distance due to buildup of fluid in alveoli Decrease in lung surface area All of the above 7 Hemoglobin Binds oxygen very tightly under all circumstances Is almost 100% saturated with oxygen when oxygen partial pressure is 100 mmHg Requires the ion calcium for proper function Releases the same amount of oxygen to the tissues regardless of the tissue oxygen partial pressure. None of the above 8 During exercise, which of the following factors will cause an increase in cardiac output? A decrease in heart rate A decrease in strength of contraction A decrease in venous return and filling pressure An decrease in venous compliance None of the above. 9 Increased aerobic metabolic activity in a muscle during exercise causes: A decrease in muscle oxygen partial pressure, which leads to increased resistance in the muscle capillary bed. A decrease in muscle oxygen partial pressure, which leads to reduced resistance in the muscle capillary bed. An increased resistance in the muscle capillary bed, which leads to a decrease in muscle oxygen partial pressure An increase in muscle oxygen partial pressure, which leads to increased resistance in the muscle capillary bed. A decreased resistance in the muscle capillary bed, which leads to a decreased oxygen partial pressure. 10 Which of the following would cause an increase in stroke volume: Increased strength of contraction Increased venous return as a result of increased blood volume Increased venous return due to increased skeletal muscle pump activity Increased venous return due to increased venoconstriction. All of the above. 11 Blood flow to the intestine during moderately intense exercise Is increased to allow for increased energy acquisition Is reduced due to increased arterial blood pressure Is reduced due to increased resistance in the intestinal blood vessels Is increased due to increased resistance in the intestinal blood vessels None of the above.