The Cardiovascular System: The Heart
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Questions
What is the approximate average weight of a female heart according to the text?
View answer and explanationWhich layer of the heart wall is the thickest and responsible for pumping blood?
View answer and explanationWhat is the remnant of the foramen ovale in an adult heart called?
View answer and explanationWhich component of the cardiac conduction system is known as the pacemaker and initiates the sinus rhythm?
View answer and explanationWhat does the QRS complex on an electrocardiogram (ECG) represent?
View answer and explanationIn a resting adult, what is the approximate volume of blood contained in the ventricles at the end of atrial systole, also known as end diastolic volume (EDV)?
View answer and explanationThe first heart sound, S1 or 'lub,' is created by the closing of which valves?
View answer and explanationWhat is the formula for calculating cardiac output (CO)?
View answer and explanationAccording to the Frank-Starling mechanism, what is the relationship between ventricular stretch and the force of contraction?
View answer and explanationFrom which embryonic tissue does the heart primarily form?
View answer and explanationWhat is the total time elapsed from the initiation of the impulse in the SA node until the depolarization of the ventricles?
View answer and explanationWhich ventricle has a much thicker myocardium and why?
View answer and explanationWhat is the function of the chordae tendineae and papillary muscles?
View answer and explanationWhich coronary artery branch is also known as the left anterior descending artery (LAD) and follows the anterior interventricular sulcus?
View answer and explanationWhat is the term for the property of cardiac muscle that allows it to initiate an electrical potential at a fixed rate?
View answer and explanationWhat is the approximate inherent firing rate of the atrioventricular (AV) node if the SA node were not functioning?
View answer and explanationThe prolonged plateau phase in the action potential of cardiac contractile cells is primarily due to the influx of which ion?
View answer and explanationWhat is the term for the period of the cardiac cycle when the heart muscle is relaxed and the chambers fill with blood?
View answer and explanationApproximately what percentage of ventricular filling occurs passively while the atria are in diastole?
View answer and explanationWhat is the typical average resting heart rate for an adult?
View answer and explanationThe cardioaccelerator and cardioinhibitory centers that provide nervous control over heart rate are located in which part of the brain?
View answer and explanationWhat is the atrial reflex, also known as the Bainbridge reflex?
View answer and explanationWhich of the following is considered a negative inotropic factor, meaning it decreases the force of heart contraction?
View answer and explanationIn the developing fetus, which structure forms the left ventricle?
View answer and explanationWhat is the typical average cardiac output (CO) for a resting adult, as calculated from the numbers provided in the chapter?
View answer and explanationThe bicuspid valve, also known as the mitral valve, separates which two chambers of the heart?
View answer and explanationWhat is the approximate duration of the absolute refractory period for cardiac contractile muscle?
View answer and explanationThe second heart sound, S2 or 'dub', is associated with the closing of which set of valves?
View answer and explanationThe difference between maximum and resting cardiac output is known as what?
View answer and explanationIn the fetal heart, what is the function of the foramen ovale?
View answer and explanationIn a healthy young adult, at what heart rate does cardiac output typically begin to decrease because the ventricles do not have enough time to fill?
View answer and explanationWhat is the term for the initial phase of ventricular systole where pressure increases but the volume of blood in the chamber remains constant?
View answer and explanationThe left coronary artery distributes blood to all of the following areas EXCEPT:
View answer and explanationWhat is the approximate duration of a complete cardiac cycle?
View answer and explanationThe Purkinje fibers have a fast inherent conduction rate, allowing the electrical impulse to reach all ventricular muscle cells in about how long?
View answer and explanationA condition where the resting heart rate drops below 60 bpm is known as:
View answer and explanationParasympathetic stimulation releases which neurotransmitter to slow the heart rate?
View answer and explanationWhat is the term for the force the ventricles must develop to pump blood effectively against the resistance in the vascular system?
View answer and explanationThe human heart begins beating and pumping blood around what day after fertilization?
View answer and explanationWhich valves of the heart are also known as the atrioventricular (AV) valves?
View answer and explanationThe 'atrial kick' contributes approximately what percentage to ventricular filling?
View answer and explanationThe great cardiac vein, middle cardiac vein, and small cardiac vein all drain into which large, thin-walled vein on the posterior surface of the heart?
View answer and explanationIn a 12-lead ECG, how many electrodes are placed on the chest?
View answer and explanationWhat is the term for the fat-filled grooves on the superior surfaces of the heart where major coronary blood vessels are located?
View answer and explanationWhich specialized myocardial conductive fibers spread the impulse from the apex of the heart toward the atrioventricular septum and base?
View answer and explanationWhat is the approximate duration of the plateau phase in the action potential of a cardiac contractile cell?
View answer and explanationAn abnormally enlarged heart muscle, which is often undiagnosed and can cause sudden death in young people, is known as what?
View answer and explanationWhat term describes the average stroke volume (SV) for a resting 70-kg individual?
View answer and explanationDuring which phase of the cardiac cycle are all four heart valves closed for a brief period?
View answer and explanationIn the primitive heart tube, which region develops into the posterior portion of the right atrium, the SA node, and the coronary sinus?
View answer and explanation