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| 1 | |
Erythrocyte production is regulated mainly by |
| | A) | the liver. |
| | B) | the kidneys. |
| | C) | the lungs. |
| | D) | the thymus and bone marrow. |
| | E) | the spleen. |
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| 2 | |
Doubling the radius of the arterioles in an organ would ___________ the blood flow to the organ. |
| | A) | Double. |
| | B) | Quadruple. |
| | C) | Increase by eight-fold. |
| | D) | Increase by a factor of sixteen. |
| | E) | Increase by a factor of thirty-two. |
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| 3 | |
Which of the following statements regarding the pacemaker activity of the heart is true? |
| | A) | The pacemaker of the heart is normally in the AV node. |
| | B) | Heart rate is increased when adrenergic receptors on the pacemaker cells are activated. |
| | C) | The pacemaker potential is caused by a spontaneous decrease in membrane permeability to Na+. |
| | D) | A and B. |
| | E) | B and C. |
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| 4 | |
Which of the following statements regarding the cardiac cycle is true? |
| | A) | The AV valves are open during most of diastole. |
| | B) | The aortic valve is closed throughout the interval between the QRS and T waves. |
| | C) | The first heart sound is the opening of the aortic valve. |
| | D) | The ventricular pressure is greater than the aortic pressure during isovolumetric contraction. |
| | E) | None of the above is true. |
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| 5 | |
Following hemorrhage, reflexes are triggered that attempt to compensate for the blood loss. As a result of the blood loss and the reflex mechanisms, which of the following will be true, compared to prehemorrhage values? |
| | A) | Heart rate will be increased. |
| | B) | Stroke volume will be decreased. |
| | C) | Capillary filtration will be decreased. |
| | D) | A and B. |
| | E) | A,B and C. |
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| 6 | |
Immediately after a hemorrhage, baroreceptors_________ their firing rate, signaling the medullary cardiovascular center to __________the activity of the sympathetic nerves to the heart, arterioles and veins. The result of this reflex would be to increase the__________and____________over normal and to bring the ___________,____________and ____________back toward pre-hemorrhage values. |
| | A) | increase; increase; stroke volume and peripheral resistance; heart rate, cardiac output and arterial blood pressure. |
| | B) | decrease; increase; heart rate and peripheral resistance; stroke volume, cardiac output and arterial blood pressure. |
| | C) | increase; decrease; heart rate and peripheral resistance; stroke volume, cardiac output and arterial blood pressure. |
| | D) | decrease; increase; heart rate and arterial blood pressure; peripheral resistance, stroke volume and cardiac output. |
| | E) | decrease; decrease; heart rate and cardiac output; stroke volume, peripheral resistance and arterial blood pressure. |
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| 7 | |
Compared with resting levels of blood flow, during strenuous exercise |
| | A) | blood flow to the heart, brain, and skeletal muscles would increase. |
| | B) | blood flow to the kidneys and abdominal organs would decrease. |
| | C) | blood flow to the skin and brain would decrease. |
| | D) | A and B. |
| | E) | B and C. |
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| 8 | |
The formation of plasmin |
| | A) | occurs as a result of activation of clotting factors in the blood. |
| | B) | results in the dissolution of the blood clot. |
| | C) | is part of a cascade of reactions in response to injury to blood vessels. |
| | D) | is a direct result of activation of plasminogen. |
| | E) | is described by all of the above. |
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| 9 | |
The left ventricle ejects a larger volume of blood during systole than does the right ventricle because the left ventricular pressure is greater than the right. |
| | A) | True |
| | B) | False |
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| 10 | |
Because sympathetic stimulation of the arterioles causes vasoconstriction, the sympathetic nerves play no role in reflex vasodilation. |
| | A) | True |
| | B) | False |
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