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