A&PII Chapter 18 Quiz

24 July 2022
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question
Which statement is correct regarding the ventricles? A) the right ventricle empties into pulmonary trunk B) the left ventricle empties into pulmonary circuit C) the left ventricle has a thinner wall than the right ventricle The right ventricle forms a complete circle in cross section
answer
A) the right ventricle empties into pulmonary trunk The right ventricle empties into the pulmonary trunk and the pulmonary circuit.
question
If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________. A) threshold is released more quickly and heart rate would increased B) heart rate would decrease, but blood pressure would rise due to the excess sodium present C) tetanic contraction would occur due to the short absolute refractory period of cardiac muscle D)potassium channels compensate and no change in heart rate would occur
answer
A) threshold is released more quickly and heart rate would increased
question
Which of the following does NOT deliver deoxygenated blood to the heart? A) coronary sinus B) pulmonary veins C) superior vena cava D) inferior vena cava
answer
B) pulmonary veins The pulmonary veins deliver oxygenated blood to the left atrium.
question
What best describes afterload? A) contractility of cardiac muscle B) degree of stretch of the heart muscle C) back pressure exerted by arterial blood D) cardiac reserve
answer
B) back pressure exerted by arterial blood Afterload refers to the back pressure exerted by arterial blood, or the pressure that must be overcome for the ventricles to eject blood.
question
What structures connect the individual heart muscle cells? A)chord tendineae B) intercalated disc C) trabaculae carneae D) anastomoses
answer
B) intercalated disc Intercalated discs connect the heart muscle cells. They include desmosomes (anchoring junctions) and gap junctions (communicating junctions).
question
Which of the events below does NOT occur when the semilunar valves are open? A) blood enters pulmonary arteries and the aorta B) AV valves are closed C) ventricles are in systole D)ventricles are in diastole
answer
D) ventricles are in diastole
question
The order of impulse conduction in the heart, from beginning to end, is __________. A) SA node, bundle branch, AV node, bundle of his, and purkinje fibers B) SA node, bundle of his, AV node, bundle branch and parkinje fibers C) SA node, AV node, bundle of his, bundle branch, and purkinje fibers D) SA node, bundle branches, bundle of His, AV node, and Purkinje fibers
answer
C) SA node, AV node, bundle of his, bundle branch, and purkinje fibers The impulses of the heart originate at the SA node (pacemaker). The impulse is then transmitted to the AV node (atrioventricular node), where the impulse slows down to allow the atria to completely contract and thereby fill the adjacent ventricles. The AV node then transmits the impulse to the bundle of His, which branches into left and right bundle branches. The bundle branches give rise to the Purkinje fibers, which transmit the impulse to the ventricle walls and stimulate ventricular contraction.
question
In an ischemic heart, the affected cardiac muscle cells are likely to have an altered ______. A) number of Z disc B) number of desmosomes C) number of slow Ca+2 channels D) resting member potential
answer
D) resting membrane potential Ischemia is cell and tissue damage that result from a lack of proper blood and oxygen delivery. The damaged tissue is normally replaced by scar tissue that lacks the normal cell structure of the original tissue. So "scarred" cardiac muscle would lack the pumps and channels that are necessary to establish resting membrane potential.
question
The right side of the heart is considered the systemic circuit pump. T/F
answer
False The right side of the heart pumps oxygen-poor blood to the lungs to be re-oxygenated. For this reason, the right side of the heart is considered the pulmonary circuit pump. The left side of the heart pumps blood to the body, and is therefore considered the systemic circuit pump.
question
Select the correct statement about the heart valves. A) the tricuspid valve divided the left atrium from left ventricles B) the mitral valve separated the right atrium from the right ventricles C) aortic and pulmonary semilunar valve control the flow of blood into the heart D) the atrioventricular(AV) valve prevent back flow of blood into atria during ventricular contraction
answer
D) the atrioventricular(AV) valve prevent back flow of blood into atria during ventricular contraction
question
During contraction of heart muscle cells ________. A) some calcium enters the cell from the extracellular space and trigger the release of large amounts of calcium from intracellular stores B) calcium is prevented from entering cardiac fibers that have been stimulated C) all of the calcium required for contraction comes from storage in the SR D) the action potential is prevented from spreading from cell to cell by gap junction
answer
A) some calcium enters the cell from the extracellular space and trigger the release of large amounts of calcium from intracellular stores
question
The papillary muscles contract after the other ventricular muscles so that they can take up the slack on the chordae tendineae before the full force of ventricular contractions sends blood against the atrioventricular (AV) valve flaps. T/F
answer
False
question
Hemorrhage with a large loss of blood causes ________. A) a rise in blood pressure due to change in cardiac output B) no change in blood pressure but a slower heart rate C) lowering of blood pressure due to change in cardiac output D) no change in blood pressure but a change in respiration
answer
C) a lowering of blood pressure due to change in cardiac output
question
Tissues damaged by myocardial infarction are replaced by connective tissue. T/F
answer
True
question
Failure in a particular chamber of the heart tends to cause a backup of blood in the lungs, known as pulmonary congestive heart failure. Failure of which chamber of the heart would lead to such a backup? A) right atrium B) right ventricle C) left ventricle D) left atrium
answer
C) left ventricle Failure in the left ventricle can cause increased blood hydrostatic pressure in the lungs, causing fluid buildup in the alveoli.
question
As your muscles contract during activity, more blood is returned to the heart. Which variable would be affected and what would be the outcome of this action? A) end systolic volume would be increased, which would increase cardiac output B) prelude would be increase, which would increase cardiac output C) contractility would be increased, which would increase cardiac output D) after load would increase, which woulds increase cardiac output
answer
B) preload would be increased, which would increased cardiac output More blood returning to the heart would increase the stretch of the heart muscle. This increases the preload, which would have the outcome of increasing cardiac output by increasing stroke volume.
question
What does the QRS wave of the electrocardiogram (ECG) represent? A) ventricular depolarization B) atrial depolarization C) atrial repolarization D)ventricular repolarization
answer
A) ventricular depolarization
question
During which portion of the electrocardiogram do the atrioventricular valves close, correlating with the first heart sound ("lub")? A) T wave B) R-S waves C) P-R interval D) P wave
answer
B) R-S waves When the ventricles enter systole, the atrioventricular valves close. This valve closure is associated with the first heart sound, the "lub."
question
Why are gap junctions a vital part of the intercellular connection of cardiac muscles? A) gap junction forms intercellular connection B) Gap junction allow action potentials to spread to connected cells C) gap junction contract when stimulated, strengthening the force of cardiac cell contraction D) Gap junction allow calcium to enter the cell, triggering calcium release from SR
answer
B) Gap junction allow action potentials to spread to connected cells Gap junctions are a form of electrical synapse that allow action potentials to spread to connected cells. This property allows the signal to spread efficiently through the heart.
question
The role of the chordae tendineae is to open the AV valves at the appropriate time. T/F
answer
False The role of the chordae tendineae is to anchor the AV valves against the large pressure changes that occur as the ventricles contract.
question
Which of the following is NOT a factor that increases stroke volume? A) increasing afterload B)increasing sympathetic stimulation C) increasing contractility D) increase preload
answer
A) increasing afterload Increasing afterload decreases stroke volume.
question
Which of these vessels returns blood to the left atrium of the heart? A) pulmonary veins B) pulmonary trunk C) superion vena cava D) coronary sinus
answer
A) pulmonary veins The pulmonary veins transport oxygen-enriched blood from the lungs to the left atrium.
question
Which statement regarding cardiac muscle structure is accurate? A) myofibrils of cardiac muscle tissue very in diameter and branch extensively B) cardiac muscle cells are independent of one another both structurally and functionally C) cardiac cells are long, cylindrical and multinucleated D) cardiac cells possess few mitochondria
answer
A) myofibrils of cardiac muscle tissue very in diameter and branch extensively The myofibrils of cardiac muscle have various diameters; they also branch in order to maintain connections, via intercalated discs, with other muscle cells.
question
Given an end diastolic volume (EDV) of 120 ml / beat and an end systolic volume (ESV) of 50 ml / beat, the stroke volume (SV) would be ________. A) 120mL/beats B) 50mL/ beats C) 170 mL/ beats D) 70 mL/ beats
answer
D) 70 mL/ beats
question
Congestive heart failure means that the pumping efficiency of the heart is depressed so that there is inadequate delivery of blood to body tissues. T/F
answer
True
question
The atrioventricular (AV) valves are closed ________. A) while the atria are contracting B) by the movement of blood from atria to ventricles C) when the ventricles are in systole D) when ventricles are in diastole
answer
C) when the ventricles are in systole
question
Heart tissue is supplied with nutrients primarily by diffusion from the heart chambers through the myocardium. T/F
answer
False
question
At what rate does the sinoatrial (SA) node depolarize? A)30 times per minutes B) 40 times per minutes C) 50 times per minutes D) 75 times per minutes
answer
D) 75 times per minutes The sinoatrial node typically depolarizes spontaneously about 75 times per minute, although this can vary in different individuals. This rate is directly modulated by the autonomic nervous system.
question
What is the period during the cardiac cycle when the ventricles are completely closed and blood volume in them remains constant as the ventricles contract? A)isovolumetric relaxation phase B)ventricular filling C) ventricular ejection D)isovolumetric contraction phase
answer
D) isovolumetric contraction phase The prefix -iso means "equal," so during any isovolumetric stage the volume does not change.
question
Which heart chamber receives oxygenated blood from the lungs? A)right ventricle B)right atrium C)left ventricle D) left atrium
answer
D) left atrium Oxygenated blood from the lungs returns to the left atrium of the heart.
question
A) Quiescent period B) ischemia C) ectopic focus D) infarction E) fibrillation
answer
A) Total heart relaxation. B) Heart muscle is deprived of oxygen. C) An abnormal pacemaker. D)Death of heart muscle cells E) A condition of rapid and irregular or out-of-phase contraction of heart muscle cells.
question
Select the correct statement about cardiac output. A) A slow heart rate increases end diastolic volume, stroke volume, and force of contraction. B) If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased. C) Stroke volume increases if end diastolic volume decreases. D) Decreased venous return will result in increased end diastolic volume.
answer
A)A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.