Quiz 2: Heart – Flashcards
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Normal heart sounds are caused by which of the following events?
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closure of the heart valves
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Which of the events below does not occur when the semilunar valves are open?
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Ventricles are in diastole.
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Hemorrhage with a large loss of blood causes ________.
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a lowering of blood pressure due to change in cardiac output
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The left ventricular wall of the heart is thicker than the right wall in order to ________.
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pump blood with greater pressure
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Damage to the ________ is referred to as heart block.
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AV node
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The P wave of a normal electrocardiogram indicates ________.
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atrial depolarization
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Blood within the pulmonary veins returns to the ________.
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left atrium
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Small muscle masses attached to the chordae tendineae are the ________.
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papillary muscles
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The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________.
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angina pectoris
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To auscultate the aortic semilunar valve, you would place your stethoscope in the ________.
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second intercostal space to the right of the sternum
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The source of blood carried to capillaries in the myocardium would be the ________.
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coronary arteries
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The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________.
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pumps blood against a greater resistance
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Which of the following factors does not influence heart rate?
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skin color
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Which of the following is not an age-related change affecting the heart?
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thinning of the valve flaps
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If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________.
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decreased delivery of oxygen
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If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells ________.
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tetanic contractions might occur, which would stop the heart's pumping action
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Norepinephrine acts on the heart by ________.
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causing threshold to be reached more quickly
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If the vagal nerves to the heart were cut, the result would be that ________.
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the heart rate would increase by about 25 beats per minute
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Foramen ovale ________.
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connects the two atria in the fetal heart
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Which vessel of the heart receives blood during right ventricular systole?
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pulmonary trunk
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Which of these vessels receives blood during ventricular systole?
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both the aorta and pulmonary trunk
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Which of the following is not part of the conduction system of the heart?
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AV valve
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The tricuspid valve is closed ________.
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when the ventricle is in systole
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When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________.
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noticing the thickness of the ventricle walls
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Select the correct statement about the heart valves.
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The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.
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Select the correct statement about the function of myocardial cells.
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The entire heart contracts as a unit or it does not contract at all.
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Select the correct statement about the structure of the heart wall.
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The myocardium is the layer of the heart that actually contracts.
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Compared to skeletal muscle, cardiac muscle ________.
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has gap junctions that allow it to act as a functional syncytium
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During the period of ventricular filling ________.
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blood flows passively through the atria and the open AV valves into the ventricles
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The second heart sound is heard during which phase of the cardiac cycle?
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isovolumetric relaxation
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The time of day most hazardous for heart attacks is ________.
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morning
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If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________.
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threshold is reached more quickly and heart rate would increase
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Select the correct statement about cardiac output.
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A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.
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During contraction of heart muscle cells ________.
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some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores
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Isovolumetric contraction ________.
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refers to the short period during ventricular systole when the ventricles are completely closed chambers
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Commotio cordis is heart failure due to a ________.
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relatively mild blow to the chest that occurs during a vulnerable interval (2 ms) when the heart is repolarizing
