Anatomy And Physiology: The Heart Pt. 2
The Cardiac Cycle, Cardiac Output, Cardiac Disease, Exercise
- 1.
How does the heart change pressure in order to produce flow?
- A.
By repolarizing to increase pressure in a chamber
- B.
By relaxing to decrease pressure in a chamber
- C.
By contracting to increase pressure in a chamber
- D.
By depolarizing to decrease pressure in a chamber
Correct Answer
C. By contracting to increase pressure in a chamberExplanation
The heart changes pressure in order to produce flow by contracting to increase pressure in a chamber. When the heart contracts, it squeezes the blood, increasing the pressure inside the chamber. This increased pressure forces the blood to flow out of the chamber and into the next part of the circulatory system.Rate this question:
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- 2.
How are flow and pressure related?
- A.
Flow will increase if the difference in pressure between two points decreases
- B.
Flow will increase if the difference in pressure between two points increases
- C.
Flow will go backwards if there is no difference in pressure between two points
- D.
If flow between two points increases, then the difference in pressure will increase
Correct Answer
B. Flow will increase if the difference in pressure between two points increasesExplanation
The correct answer is that flow will increase if the difference in pressure between two points increases. This is because flow is directly proportional to the pressure difference. When the pressure difference increases, it creates a greater force or driving pressure for the fluid to flow, resulting in an increase in flow rate.Rate this question:
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- 3.
Clogged arteries may cause reduced flow of blood from the heart. Why wold there be less flow?
- A.
Because it increases afterload
- B.
Because it decreases resistance
- C.
Because it decreases preload
- D.
Because it increases contractility
Correct Answer
A. Because it increases afterloadExplanation
When arteries are clogged, it leads to increased afterload. Afterload refers to the force that the heart needs to generate in order to pump blood out of the heart and into the arteries. When the arteries are clogged, the heart needs to work harder to overcome the increased resistance and push blood through the narrowed arteries. This increased afterload results in reduced flow of blood from the heart, as the heart is unable to pump blood effectively against the increased resistance caused by the clogged arteries.Rate this question:
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- 4.
Which of the following will cause the aortic semilunar valve to close?
- A.
When pressure in the left ventricule is higher than pressure in the left atrium
- B.
When pressure in the aorta is higher than pressure in the left ventricle
- C.
When pressure in the left ventricle is higher than pressure in the aorta
- D.
When pressure in the left atrium is higher than pressure in the aorta
Correct Answer
B. When pressure in the aorta is higher than pressure in the left ventricleExplanation
When the pressure in the aorta is higher than the pressure in the left ventricle, it indicates that the blood has been pumped out of the left ventricle and into the aorta. This increase in pressure causes the aortic semilunar valve to close, preventing the backflow of blood from the aorta back into the left ventricle. This closure ensures that blood flows in the correct direction, from the heart to the rest of the body, maintaining the efficiency of the circulatory system.Rate this question:
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- 5.
Which of the following is associated with the second heart sound?
- A.
Depolarization of the atria
- B.
Closing of the atriventricular valves
- C.
The rush of blood from the atria to the ventricles
- D.
Pressure in the ventricles become lower than pressure in the great arteries
Correct Answer
D. Pressure in the ventricles become lower than pressure in the great arteriesExplanation
The second heart sound is associated with the closing of the atrioventricular valves. This occurs when the pressure in the ventricles becomes lower than the pressure in the great arteries, causing the valves to close.Rate this question:
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- 6.
Which of the following will happen first as the ventricles begin to contract?
- A.
Semilunar valves will close
- B.
Atriventricular valves will open
- C.
Semilunar valves will open
- D.
Atrioventricular valves will close
Correct Answer
D. Atrioventricular valves will closeExplanation
As the ventricles begin to contract, the pressure inside the ventricles will increase. This increased pressure will cause the atrioventricular valves (also known as the mitral and tricuspid valves) to close. This closure prevents the backflow of blood from the ventricles into the atria. Therefore, the atrioventricular valves will close first before any other event mentioned in the options.Rate this question:
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- 7.
What do isovolumetric contraction and isovolumetric relaxation have in common?
- A.
The semilunar valves are closed
- B.
The volume of blood in the ventricles remains the same
- C.
The atrioventricular valves are closed
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
Isovolumetric contraction and isovolumetric relaxation both occur during the cardiac cycle and involve the closure of valves. During isovolumetric contraction, the semilunar valves are closed to prevent blood from flowing back into the atria, while the atrioventricular valves are also closed to prevent blood from flowing back into the atria. Similarly, during isovolumetric relaxation, the semilunar valves remain closed to prevent blood from flowing back into the ventricles, and the atrioventricular valves also remain closed. Additionally, in both processes, the volume of blood in the ventricles remains the same, hence all of the above statements are true.Rate this question:
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- 8.
The semilunar valves are open, and the ventricles are contracting. What phase of the cardiac cycle is this?
- A.
Isovolumetric relaxation
- B.
Rapid ventricular filling
- C.
Ventricular ejection (systole)
- D.
Isovolumetric contraction
Correct Answer
C. Ventricular ejection (systole)Explanation
During ventricular ejection (systole), the semilunar valves are open, allowing blood to be pumped out of the ventricles and into the arteries. The ventricles are contracting, generating enough pressure to overcome the resistance in the arteries and push the blood forward. This phase marks the peak of the cardiac cycle where the ventricles are forcefully ejecting blood, resulting in systolic pressure.Rate this question:
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- 9.
Which of the following is occuring at the same time that depolarization is spreading through the AV Node?
- A.
Ventricles are contracting
- B.
Atria are contracting
- C.
Ventricles are relaxing
- D.
Atria are relaxing
Correct Answer
B. Atria are contractingExplanation
During the spread of depolarization through the AV Node, the atria are contracting. This is because the AV Node is responsible for transmitting electrical signals from the atria to the ventricles, causing them to contract. Therefore, while depolarization is occurring in the AV Node, the atria are also contracting in order to pump blood into the ventricles.Rate this question:
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- 10.
At which of the following points do the ventricles have the smallest volume of blood?
- A.
At the end of isovolumetric relaxtion
- B.
At the end of rapid ventricular filling
- C.
At the beginning of ventricular ejection
- D.
At the end of isovolumetric contraction
Correct Answer
A. At the end of isovolumetric relaxtionExplanation
At the end of isovolumetric relaxation, the ventricles have the smallest volume of blood. During this phase, the ventricles are in a relaxed state, and the pressure in the ventricles is low. The atrioventricular valves are closed, preventing blood from entering the ventricles. As a result, the ventricles are not filling with blood, leading to the smallest volume of blood in the ventricles at this point.Rate this question:
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- 11.
Which of the following statements about the cardiac output (CO) are true?
- A.
CO is a measure of how much blood the heart pumps in one minute
- B.
SV x HR = CO
- C.
CO increases in exercise due to increases in both SV and HR
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
The cardiac output (CO) is a measure of the amount of blood that the heart pumps in one minute. It is calculated by multiplying the stroke volume (SV), which is the amount of blood pumped with each heartbeat, by the heart rate (HR), which is the number of times the heart beats per minute. During exercise, both the stroke volume and heart rate increase, leading to an increase in the cardiac output. Therefore, all of the given statements about the cardiac output are true.Rate this question:
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- 12.
If the right ventricle had lower output than the left, which of the following would result?
- A.
Systemic edema
- B.
Increased afterload for right ventricle
- C.
Right ventricular hypertrophy
- D.
All of the above
Correct Answer
A. Systemic edemaExplanation
If the right ventricle had lower output than the left, it would result in systemic edema. This is because the right ventricle is responsible for pumping blood to the lungs to receive oxygen, and if it has a lower output, there would be a buildup of fluid in the systemic circulation, leading to edema. Increased afterload for the right ventricle and right ventricular hypertrophy may also occur as compensatory mechanisms, but the primary consequence would be systemic edema.Rate this question:
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- 13.
Cor pulmonale is a type of _______ that originates from obstruction in the pulmonary circulation.
- A.
Angina pectoris
- B.
Congestive heart failure
- C.
Myocardial infarction
- D.
Atherosclerosis
Correct Answer
B. Congestive heart failureExplanation
Cor pulmonale is a type of congestive heart failure that originates from obstruction in the pulmonary circulation. This condition occurs when the right side of the heart becomes enlarged and weakened due to increased pressure in the lungs. It is commonly caused by chronic lung diseases such as chronic obstructive pulmonary disease (COPD) or pulmonary embolism. The obstruction in the pulmonary circulation leads to increased resistance and pressure in the right side of the heart, eventually causing it to fail in pumping blood effectively.Rate this question:
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- 14.
Which of the following would definitely cause a decrease in cardiac output?
- A.
An increase in heart rate with no change in stroke volume
- B.
A decrease in stroke volume with no change in heart rate
- C.
An increase in stroke volume with a decrease in heart rate
- D.
An increase in stroke volume with no change in heart rate
Correct Answer
B. A decrease in stroke volume with no change in heart rateExplanation
A decrease in stroke volume means that the amount of blood pumped out of the heart with each heartbeat is reduced. This would result in a decrease in cardiac output, as cardiac output is the total amount of blood pumped by the heart per minute. If there is no change in heart rate, it means that the number of heartbeats per minute remains the same. Therefore, the combination of a decrease in stroke volume and no change in heart rate would definitely cause a decrease in cardiac output.Rate this question:
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- 15.
If venous return decreased, which of the follwing would likely happen as a result?
- A.
Afterload would increase
- B.
The ventricles would contract more forcefully
- C.
The ventricles would contract less forcefully
- D.
Preload would increase
Correct Answer
C. The ventricles would contract less forcefullyExplanation
If venous return decreases, it means that less blood is returning to the heart from the veins. This would result in a decrease in the amount of blood available to fill the ventricles during diastole, leading to a decrease in preload. Since preload is the amount of blood in the ventricles before contraction, a decrease in preload would cause the ventricles to contract with less force during systole. Therefore, the correct answer is that the ventricles would contract less forcefully.Rate this question:
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- 16.
Which of the following is an example of postive feedback in the circulatory system?
- A.
When blood pressure drops, the heart is stimulated to increase cardiac output and restore pressure.
- B.
If more blood enters the ventricles, then the ventricles will pump out more blood.
- C.
After depolarizing, cardiac myocytes repolarize (or return to the resting membrane potential)
- D.
Unbalanced ventricular output leads to failure of one side of the heart, followed by failure of the other side of the heart.
Correct Answer
D. Unbalanced ventricular output leads to failure of one side of the heart, followed by failure of the other side of the heart.Explanation
This answer correctly identifies unbalanced ventricular output as an example of positive feedback in the circulatory system. Positive feedback occurs when a change in a system amplifies the original change, leading to further changes in the same direction. In this case, unbalanced ventricular output causes one side of the heart to fail, which then leads to failure of the other side of the heart, resulting in a continuous cycle of worsening heart failure.Rate this question:
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- 17.
If blood pressure in the aorta or caotid arteries suddenly increased, how would the baroreflex restore blood pressure?
- A.
It would increase heart rate
- B.
It would decrease heart rate
- C.
It would increase stroke volume
- D.
It would decrease stroke volume
Correct Answer
B. It would decrease heart rateExplanation
When blood pressure in the aorta or carotid arteries suddenly increases, the baroreflex mechanism would activate to restore blood pressure. This reflex involves sensing the increased pressure and sending signals to the brain. In response, the brain would initiate a decrease in heart rate through the parasympathetic nervous system. This decrease in heart rate would help to lower blood pressure and restore it to normal levels.Rate this question:
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- 18.
Which of the following statements is true regarding central regulation of heart rate (HR)?
- A.
The cardioinhibitory center increases HR through parasympathetic neurons that release ACh and hyperpolarize the SA node.
- B.
The cardioacceleratory center decreases HR through sympathetic neurons that release norepinephrine and bind to B-receptors
- C.
Patients with weak hearts are comtimes given drugs called B-Blockers which prevents sympathetic stimulation of HR.
- D.
All of the above are true
Correct Answer
C. Patients with weak hearts are comtimes given drugs called B-Blockers which prevents sympathetic stimulation of HR.Explanation
B-Blockers are drugs that block the effects of norepinephrine on B-receptors, which are found in the heart. By blocking these receptors, B-Blockers prevent sympathetic stimulation of the heart rate (HR). This is beneficial for patients with weak hearts because it helps to reduce the workload on the heart and improve its efficiency. Therefore, the statement "Patients with weak hearts are sometimes given drugs called B-Blockers which prevents sympathetic stimulation of HR" is true.Rate this question:
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- 19.
Which of the following influence stroke volume?
- A.
End of systolic volume
- B.
Cardiac output
- C.
Contractility
- D.
Heart rate
Correct Answer
C. ContractilityExplanation
Contractility refers to the force of contraction of the heart muscle. It is the ability of the heart to contract and pump blood effectively. An increase in contractility leads to an increase in stroke volume, which is the amount of blood pumped out of the heart with each heartbeat. Therefore, contractility directly influences stroke volume.Rate this question:
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- 20.
Which of the following decreases stroke volume?
- A.
Increased afterload
- B.
Increased heart rate
- C.
Decreased preload
- D.
Increased contractility
Correct Answer
A. Increased afterloadExplanation
Increased afterload refers to an increase in the resistance that the heart has to overcome in order to pump blood out of the left ventricle and into the systemic circulation. This can be caused by conditions such as hypertension or aortic stenosis. When afterload increases, the heart has to work harder to overcome this resistance, which can lead to a decrease in stroke volume. Stroke volume is the amount of blood pumped out of the heart with each contraction, so if afterload increases, the heart may not be able to pump as much blood out, resulting in a decrease in stroke volume.Rate this question:
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- 21.
You have a patient whose heart cannot generate sufficient force during contraction. You have a range of drugs to choose from, but in general, you know that you want a drug that:
- A.
Increases intracellular Ca2+
- B.
Increases intracellular K+
- C.
Decreases extracellular Na+
- D.
Is negative chronotropic
Correct Answer
A. Increases intracellular Ca2+Explanation
The correct answer is "increases intracellular Ca2+". This is because increasing intracellular Ca2+ levels can help improve the force of contraction in the heart. Ca2+ is essential for the process of muscle contraction, including the contraction of cardiac muscle. By increasing intracellular Ca2+ levels, the heart muscle can generate more force during contraction, which can help improve cardiac output and overall heart function.Rate this question:
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- 22.
Hypertension is an example of:
- A.
Increased contractility
- B.
Increased preload
- C.
Increased afterload
- D.
Decreased afterload
Correct Answer
B. Increased preloadExplanation
Hypertension is an example of increased preload. Preload refers to the amount of blood that fills the ventricles of the heart during diastole, before it contracts. In hypertension, there is an increased resistance to blood flow, causing the heart to work harder to pump blood against this resistance. This increased workload leads to an increase in the amount of blood filling the ventricles during diastole, resulting in increased preload.Rate this question:
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- 23.
The volume of blood ejected by the ventricle during one cardiac cycle is called:
- A.
End of systolic volume
- B.
Cardiac output
- C.
End of diastolic volume
- D.
Stroke volume
Correct Answer
D. Stroke volumeExplanation
The volume of blood ejected by the ventricle during one cardiac cycle is called stroke volume. It represents the amount of blood pumped out of the heart with each contraction. It is an important measure of cardiac function and is calculated by subtracting the end-diastolic volume from the end-systolic volume. Cardiac output, on the other hand, refers to the total volume of blood pumped by the heart in one minute and is calculated by multiplying the stroke volume by the heart rate.Rate this question:
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- 24.
Which of the following decreases afterload?
- A.
Increased venous return
- B.
Hypotension
- C.
Hyperkalemia
- D.
All of the above
Correct Answer
B. HypotensionExplanation
Hypotension decreases afterload. Afterload refers to the resistance that the heart has to overcome in order to pump blood out of the left ventricle and into the systemic circulation. Hypotension, or low blood pressure, reduces the resistance against which the heart has to pump, thereby decreasing afterload. This allows the heart to pump blood more easily and efficiently. Increased venous return and hyperkalemia do not directly affect afterload.Rate this question:
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- 25.
Which of the following is a long-term adjustment to exercise that you might expect to see in an athlete?
- A.
Lower stroke volume
- B.
Ventricular hypertrophy
- C.
Higher resting heart rate
- D.
All of the above
Correct Answer
B. Ventricular hypertrophyExplanation
Ventricular hypertrophy is a long-term adjustment to exercise that an athlete might expect to see. This refers to an increase in the size and strength of the heart's ventricles, which are responsible for pumping blood to the rest of the body. With regular exercise, the heart adapts by growing larger and more efficient, allowing it to pump more blood with each beat. This adaptation helps to improve athletic performance and endurance. Lower stroke volume and higher resting heart rate are not long-term adjustments to exercise, making them incorrect options.Rate this question:
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- 26.
Which of the following decribes the short-term response of the body to exercise?
- A.
Venous return decreases due to the action of the skeletal muscle pump
- B.
Proprioreceptors signal the cardiac center which increases heart rate
- C.
Preload and stroke volume decrease
- D.
All of the above
Correct Answer
B. Proprioreceptors signal the cardiac center which increases heart rateExplanation
During exercise, the body's short-term response includes various changes to adapt to the increased demand for oxygen and energy. One of these responses is the activation of proprioreceptors, which are sensory receptors located in muscles, tendons, and joints. These proprioreceptors signal the cardiac center in the brain, leading to an increase in heart rate. This increased heart rate helps to deliver more oxygen and nutrients to the working muscles. Therefore, the statement "proprioreceptors signal the cardiac center which increases heart rate" accurately describes the short-term response of the body to exercise.Rate this question:
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- 27.
The first sound of the heart is cased by ______
Correct Answer
bicuspid closingExplanation
The first sound of the heart is caused by the closing of the bicuspid valve. When the ventricles contract, the bicuspid valve, also known as the mitral valve, closes to prevent the backflow of blood into the atria. This closure creates a sound known as the first heart sound or "lub" sound. It marks the beginning of systole, the phase of the cardiac cycle where the heart is contracting and pumping blood out to the body.Rate this question:
- 28.
The second sound of the heart is caused by ________
Correct Answer
aortic semilunar valves closingExplanation
The second sound of the heart is caused by the closure of the aortic semilunar valves. When the heart contracts and pumps blood out of the left ventricle into the aorta, the aortic semilunar valves open to allow the blood flow. Once the blood is ejected, the valves quickly close to prevent backflow into the ventricle. This closure creates the second sound, known as the "dub" sound, which can be heard during a heartbeat.Rate this question:
- 29.
What is happening on the P Wave of a ECG?
Correct Answer
atria depolarizingExplanation
The P wave on an ECG represents the depolarization, or contraction, of the atria. During this time, the electrical signals in the heart cause the atria to contract and pump blood into the ventricles. This depolarization is an important step in the overall electrical activity of the heart and is recorded as a small upward deflection on the ECG.Rate this question:
- 30.
What happens on the QRS Complex of a ECG?
Correct Answer
Atrial Repolarization, Atrial repolarization, atrial repolarizationExplanation
Atrial repolarization is the process by which the atria, the upper chambers of the heart, recover from the electrical discharge that causes them to contract. This phase typically occurs simultaneously with ventricular depolarization and is generally masked on an ECG by the more dominant QRS complex, representing ventricular depolarization.Rate this question:
- 31.
What is happening on the T Wave of a ECG?
Correct Answer
ventricles repolarizingExplanation
The T wave of an ECG represents the repolarization of the ventricles. After the contraction phase (depolarization) of the ventricles, they need to reset their electrical state to prepare for the next heartbeat. This repolarization is represented by the T wave on the ECG. It shows that the ventricles are undergoing a recovery phase and getting ready for the next cycle of contraction and relaxation.Rate this question:
- 32.
What is MAP? Why is Formula 2/3 Diastolic and 1/3 systolic?
Correct Answer
average pressure in the arteries over time
because heart spends more time in diastole than systole, average weighs to reflect that.Explanation
MAP stands for Mean Arterial Pressure, which refers to the average pressure in the arteries over time. The reason why the formula for calculating MAP is 2/3 Diastolic and 1/3 Systolic is because the heart spends more time in diastole (relaxation phase) than in systole (contraction phase). Since diastole lasts longer, it contributes more to the overall average pressure in the arteries. Therefore, the formula reflects this by giving diastolic pressure more weight (2/3) and systolic pressure less weight (1/3) in calculating the MAP.Rate this question:
- 33.
What happens when the right ventricle has a higher output than the left ventricle?
Correct Answer
fluid accumulates in the pulmonary tissueExplanation
When the right ventricle has a higher output than the left ventricle, it means that more blood is being pumped into the pulmonary circulation compared to the systemic circulation. This can lead to an imbalance in the pressures within the heart and lungs. As a result, fluid may start to accumulate in the pulmonary tissue, causing pulmonary congestion or edema. This can lead to symptoms such as shortness of breath, coughing, and difficulty breathing.Rate this question:
- 34.
What happens when the left ventricle has a higher output than the right ventricle?
Correct Answer
fluid accumulates in the systemic tissueExplanation
When the left ventricle has a higher output than the right ventricle, it means that the left side of the heart is pumping more blood into the systemic circulation than the right side is receiving from the body. This can lead to an imbalance in the circulation, causing fluid to accumulate in the systemic tissues. This fluid buildup can result in edema, causing swelling and discomfort in various parts of the body.Rate this question:
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