Functions Of The Heart! Trivia

Cardiac output refers to the amount of blood pumped by the heart in a minute. It is determined by two factors: heart rate and stroke volume. Heart rate is the number of times the heart beats per minute, while stroke volume is the amount of blood pumped out of the heart with each beat. Therefore, the correct answer is stroke volume, as it directly contributes to the calculation of cardiac output.

Bradycardia refers to a heart rate of fewer than 60 beats per minute. This term is used to describe a slower than normal heart rate, which can be caused by various factors such as certain medications, underlying heart conditions, or an imbalance in the electrical signals that regulate the heart's rhythm. Bradycardia can lead to symptoms like fatigue, dizziness, and shortness of breath, and may require medical intervention depending on the severity and underlying cause.

The vagus nerve is a cranial nerve that is part of the parasympathetic nervous system. It is responsible for controlling various involuntary functions in the body, such as regulating heart rate, digestion, and respiratory rate. The parasympathetic nervous system is often referred to as the "rest and digest" system, as it promotes relaxation and conservation of energy. Therefore, the statement "parasympathetic" accurately describes the vagus nerve's role in the body.

Cardiac output is the amount of blood pumped by the heart per minute. It is determined by two factors: heart rate, which is the number of times the heart beats per minute, and stroke volume, which is the amount of blood pumped out of the heart with each beat. When the heart rate increases or the stroke volume increases, the cardiac output also increases. Therefore, the correct answer is that cardiac output is determined by heart rate and stroke volume.

Heart rate and stroke volume are two important factors that determine cardiac output. Cardiac output refers to the amount of blood pumped by the heart in a minute. Heart rate is the number of times the heart beats per minute, while stroke volume is the amount of blood pumped by the heart with each beat. When the heart rate increases or the stroke volume increases, the cardiac output also increases. Therefore, heart rate and stroke volume directly affect cardiac output.

Sympathetic stimulation to the heart increases heart rate because the sympathetic nervous system releases norepinephrine, which binds to beta-adrenergic receptors on the heart. This binding activates a signaling pathway that increases the rate of depolarization in the sinoatrial (SA) node, the heart's natural pacemaker. As a result, the SA node fires more frequently, leading to an increased heart rate. This sympathetic response is part of the body's fight-or-flight response, preparing the body for increased physical activity or stress.

Furosemide (Lasix) is a diuretic medication that works by increasing the excretion of water and electrolytes, particularly sodium and chloride ions, from the body. This helps to reduce fluid accumulation and relieve edema, which is a common symptom in acute ventricular failure. By eliminating excess water, furosemide helps to decrease the workload on the heart and improve cardiac function. Therefore, the administration of furosemide in acute ventricular failure aims to excrete excess water and relieve the edema.

Starling's law of the heart refers to the increase in stroke volume that occurs in response to the stretching of the heart. This law states that the more the cardiac muscle fibers are stretched, the more forcefully they contract, resulting in an increased volume of blood pumped out of the heart with each beat. This mechanism allows the heart to adapt and respond to changes in venous return and maintain an appropriate cardiac output. Therefore, Starling's law of the heart is the term that specifically describes this increase in stroke volume due to heart stretching.

Systole and diastole are terms used to describe the contraction and relaxation of the heart muscle. The myocardium is the muscular tissue of the heart, responsible for pumping blood throughout the body. During systole, the myocardium contracts, forcing blood out of the heart and into the arteries. During diastole, the myocardium relaxes, allowing the heart chambers to fill with blood. Therefore, the correct answer is myocardium.

Cardiac output refers to the amount of blood pumped by the heart in one minute. It is a measure of the heart's efficiency in delivering oxygenated blood to the body's tissues. This is calculated by multiplying the heart rate (number of heartbeats per minute) by the stroke volume (the amount of blood pumped by the heart with each beat). Therefore, cardiac output is a crucial indicator of overall cardiovascular health and function.

Acute left-sided heart failure is characterized by the inability of the left side of the heart to effectively pump blood to the rest of the body. This leads to a buildup of fluid in the lungs, causing respiratory symptoms such as dyspnea (shortness of breath) and orthopnea (difficulty breathing while lying flat). Morphine is a medication that can help relieve these respiratory symptoms by reducing anxiety, decreasing respiratory effort, and improving oxygenation. However, it does not cure the underlying cause of heart failure. Antibiotics are used to treat infections, which are not typically the cause of acute left-sided heart failure. The symptoms are not confined to the lower extremities, but rather involve the respiratory system.

During ventricular diastole, the ventricles are relaxed and the pressure inside them is low. This allows the blood to flow from the atria into the ventricles, filling them with blood. Both the AV valves, which are the tricuspid valve and the mitral valve, are closed during this phase to prevent any backflow of blood into the atria. The semilunar valves, which are the pulmonary valve and the aortic valve, are also closed at this time, preventing blood from being pumped out of the heart. Therefore, the correct answer is that the ventricles are filling with blood.

A (+) inotropic drug is most likely to increase stroke volume. Inotropic drugs increase the force of contraction of the heart muscle, leading to increased stroke volume. This means that more blood is pumped out of the heart with each contraction, resulting in an increased stroke volume.

An ejection fraction of 30% is characteristic of a failing heart. Ejection fraction is a measurement of how well the left ventricle of the heart is pumping out blood. A normal ejection fraction is typically between 50-70%. A lower ejection fraction indicates that the heart is not pumping efficiently and may be a sign of heart failure. Therefore, an ejection fraction of 30% is indicative of a failing heart.

The vagus nerve is a cranial nerve that is primarily responsible for the parasympathetic nervous system. The parasympathetic nervous system is responsible for the body's rest and digest response, which is the opposite of the "fight or flight" response associated with the sympathetic nervous system. Therefore, the term "parasympathetic" accurately describes the vagus nerve's function.

During atrial systole, the AV valves are closed, which means that the valves between the atria and ventricles are shut. This prevents the backflow of blood from the ventricles into the atria during contraction. Since the AV valves are closed, it indicates that the ventricles are relaxed and not contracting. This is an important phase in the cardiac cycle as it allows the atria to contract and fill the ventricles with blood before the next phase of ventricular systole begins.

Excess vagal stimulation to the SA node can cause bradycardia. The vagus nerve, also known as the parasympathetic nervous system, is responsible for slowing down the heart rate. When there is an overstimulation of the vagus nerve, it can lead to a decrease in the heart rate, resulting in bradycardia. This can be seen in conditions such as vasovagal syncope, where a sudden drop in heart rate and blood pressure occurs due to excessive vagal activation.

A drug that causes a (+) inotropic effect increases the force of contraction of the heart. A drug that causes a (+) dromotropic effect increases the conduction of electrical impulses through the heart. A drug that causes a (+) chronotropic effect increases the heart rate. The term "sympathomimetic" refers to drugs that mimic the effects of the sympathetic nervous system, which includes increased heart rate, increased force of contraction, and increased conduction of electrical impulses. Therefore, the correct answer is sympathomimetic.

Atropine is a drug that blocks the vagus nerve, which is responsible for slowing down the heart rate. By blocking the vagus nerve, atropine prevents its inhibitory signals from reaching the heart, leading to an increase in heart rate. Therefore, the correct answer is that atropine increases the heart rate.

An increased afterload refers to the increased pressure that the heart has to overcome in order to pump blood out of the ventricles and into the arteries. This increased pressure is often caused by conditions such as hypertension. When the afterload increases, it puts more strain on the heart and requires it to work harder in order to overcome the resistance and pump blood effectively. Therefore, the correct answer is that an increased afterload increases the work of the heart.

Digoxin is a drug used in the treatment of heart failure because it increases contractile force. This means that it enhances the strength of the heart's contractions, leading to an increase in cardiac output. Therefore, it is known as a positive inotropic agent.

Sympathetic nerve stimulation of the myocardium causes a positive inotropic effect. This means that it enhances the force of contraction of the heart muscles, leading to increased cardiac output. It does not decrease cardiac output, heart rate, or stroke volume, as these are typically associated with parasympathetic nerve stimulation.

Vagal stimulation on the heart slows the heart rate. The vagus nerve, also known as the parasympathetic nervous system, is responsible for regulating the heart rate. When the vagus nerve is stimulated, it releases acetylcholine, which binds to receptors in the heart and decreases the electrical conduction, resulting in a slower heart rate. This is known as vagal bradycardia.

The term for the sequence of events that occur during one heartbeat is called the cardiac cycle. This cycle includes the contraction and relaxation of the heart chambers, as well as the opening and closing of the heart valves. It is responsible for the rhythmic pumping of blood throughout the body.

Acute left ventricular failure occurs when the left side of the heart is unable to pump blood effectively. This leads to a build-up of fluid in the lungs, causing pulmonary edema. As the heart is unable to pump blood efficiently, fluid backs up into the lungs, leading to symptoms such as shortness of breath, coughing, and difficulty breathing. Pulmonary edema is a common consequence of acute left ventricular failure and is the most likely outcome among the given options.

A very rapid heart rate can lead to decreased ventricular filling (with blood) because when the heart beats too quickly, there is not enough time for the ventricles to fill with blood before they contract again. This can result in inadequate blood flow to the rest of the body, leading to symptoms such as dizziness, shortness of breath, and decreased exercise tolerance.

Preload refers to the volume of blood in the ventricles at the end of diastole, just before the heart contracts. It represents the amount of blood that the heart needs to pump out with each beat. Therefore, preload is the same as the end diastolic volume, which is the volume of blood in the ventricles at the end of diastole. Stroke volume, cardiac output, and cardiac reserve are related concepts but not exactly the same as the end diastolic volume.

The Starling effect refers to the phenomenon where an increase in end diastolic volume (EDV) leads to a more forceful contraction of the heart muscle, resulting in a higher stroke volume. EDV is the volume of blood in the ventricles at the end of diastole, right before systole begins. When the ventricles are filled with a greater volume of blood, the myocardial fibers are stretched, which increases their contractility. This increased contractility allows for a greater ejection of blood during systole, leading to a higher stroke volume. Therefore, the correct answer is end diastolic volume (EDV).

Stroke volume refers to the amount of blood pumped by the ventricle in one beat. It is the difference between the amount of blood in the ventricle at the end of diastole and the amount of blood remaining in the ventricle at the end of systole. Cardiac output, on the other hand, refers to the total volume of blood pumped by the ventricle in one minute. Blood volume refers to the total volume of blood in the body, while hematocrit is the percentage of red blood cells in the total blood volume.

An average stroke volume refers to the volume of blood ejected by the heart with each contraction. Therefore, it is possible for an average stroke volume to contain 70ml of blood.

Decreased blood flow through the coronary arteries can lead to angina pectoris. Angina pectoris is a condition characterized by chest pain or discomfort caused by reduced blood flow to the heart muscle. When blood flow to the heart is restricted, it can result in inadequate oxygen supply to the heart muscle, leading to chest pain. This is commonly experienced during physical exertion or emotional stress when the heart requires more oxygen. Therefore, decreased blood flow through the coronary arteries is most likely to cause angina pectoris.

Activation of beta1 adrenergic receptors is most likely to increase ejection fraction. Beta1 adrenergic receptors are located in the heart and their activation leads to increased contractility of the heart muscle, resulting in stronger contractions. This increased contractility leads to a higher ejection fraction, which is the percentage of blood pumped out of the heart with each contraction. Therefore, activating beta1 adrenergic receptors would improve the pumping efficiency of the heart and increase ejection fraction.

The formula Milliliters/beat x beats/minute defines cardiac output. Cardiac output refers to the volume of blood pumped by the heart per minute. It is calculated by multiplying the stroke volume (the amount of blood pumped by the heart with each beat) by the heart rate (number of beats per minute). This measurement is important in assessing the overall function and efficiency of the heart in delivering oxygenated blood to the body's tissues.

A beta1 adrenergic blocker is most likely to relieve an anxiety-induced tachycardia. Anxiety can cause an increase in sympathetic nervous system activity, leading to an increase in heart rate. Beta1 adrenergic blockers, also known as beta blockers, block the beta1 adrenergic receptors in the heart, reducing the effects of sympathetic stimulation. By blocking these receptors, beta blockers can slow down the heart rate and help relieve tachycardia.

A sympathomimetic drug is one that mimics the effects of the sympathetic nervous system, which is responsible for the "fight or flight" response. Beta1 adrenergic agonists stimulate the beta1 adrenergic receptors, which are found in the heart and blood vessels. This leads to an increase in heart rate and contractility, as well as dilation of blood vessels. Therefore, beta1 adrenergic agonists can be classified as sympathomimetic drugs.

An increased preload refers to an increase in the volume of blood that fills the ventricles of the heart during diastole. This increased volume stretches the myocardial fibers, allowing them to contract more forcefully during systole. As a result, the stroke volume, which is the amount of blood pumped out of the heart with each beat, increases. This is because the increased preload enhances the force of contraction, leading to a greater ejection of blood from the heart. Therefore, the correct answer is that an increased preload increases stroke volume.

Forward failure refers to the inability of the heart to pump blood effectively, leading to a backup of blood in the circulation. In the given options, the correct answer is "diminished renal blood flow stimulates the kidney to decrease urinary output and to retain Na+ and water." This is an example of forward failure because the decreased renal blood flow causes the kidneys to reduce urine production and retain sodium and water, leading to fluid overload and exacerbating the heart's pumping difficulties.

An increased myocardial contractile force refers to a positive inotropic effect. Inotropic effect refers to the ability of the heart to contract and pump blood. When there is an increased myocardial contractile force, it means that the heart muscle is able to contract more forcefully, leading to a stronger heartbeat and increased pumping of blood. This can be beneficial in conditions where the heart is weak or failing, as it helps to improve cardiac output and overall heart function.

The vagal nerve is responsible for parasympathetic innervation, which generally slows down heart rate and decreases the force of contraction. Therefore, the discharge of the vagal nerve does not happen to a ventricle, as it would have an inhibitory effect on the heart. On the other hand, activation of the beta1 adrenergic receptors, discharge of sympathetic nerves, and binding of norepinephrine to its receptor all result in increased heart rate and contractility, which are typical responses of the ventricles to sympathetic stimulation.

When the blood returns to the heart in larger amounts, it stretches the heart muscle, which triggers the sympathetic nerve. The sympathetic nerve then activates the beta1 adrenergic receptors. This activation leads to the closing of the AV valves, which prevents backflow of blood into the atria. As a result, the stroke volume, which is the amount of blood pumped out of the heart with each beat, increases. This allows for a more efficient circulation of blood throughout the body.

An increase in venous return causes an increase in cardiac output due to Starling's law of the heart. According to this law, the more the cardiac muscle fibers are stretched by an increased volume of blood returning to the heart, the greater the force of contraction. This results in an increased amount of blood pumped out of the heart with each heartbeat, leading to an increase in cardiac output.

Activation of muscarinic receptors by acetylcholine slows down the heart rate. Muscarinic receptors are found in the heart and are part of the parasympathetic nervous system. When these receptors are activated, it leads to a decrease in the firing rate of the sinoatrial (SA) node, which is responsible for generating the electrical impulses that regulate the heart rate. This ultimately results in a slower heart rate.

A stenotic aortic valve refers to a narrowing of the semilunar valve in the heart. This narrowing restricts blood flow from the left ventricle to the aorta, causing an increase in afterload. Afterload is the resistance that the left ventricle must overcome to eject blood into the aorta. As a result, the left ventricle has to work harder to pump blood out of the heart, leading to an increase in its workload. This can eventually result in left-sided heart failure if left untreated.