Question 1: What is the primary function of the heart's left ventricle?

• Pumps deoxygenated blood to the lungs.
• Pumps oxygenated blood to the entire body. (Correct answer)
• Pumps blood to the heart's right atrium.
• Regulates blood flow in the left atrium.

Correct answer: Pumps oxygenated blood to the entire body.

The left ventricle is the strongest and most muscular chamber of the heart, essential for systemic circulation. Its primary function is to pump oxygenated blood, received from the left atrium, into the aorta. From the aorta, this blood is then distributed under high pressure to all tissues and organs throughout the entire body, supplying them with vital oxygen and nutrients.

Question 2: What does the sinoatrial (SA) node do in the heart's conduction system?

• Triggers the atrial contractions and sets the heart rate.
• Slows down the electrical impulses of the heart.
• Regulates blood pressure.
• Activates the heart valves.

The sinoatrial (SA) node is often referred to as the heart's natural pacemaker. Located in the right atrium, it spontaneously generates electrical impulses that initiate the contraction of the atria. These impulses then propagate through the heart's conduction system, effectively setting the rhythm and rate of the entire heartbeat.

Question 3: Which of the following is a common symptom of cardiac arrhythmia?

• Sudden weight loss.
• Dizziness and palpitations. (Correct answer)
• Frequent coughing.
• Fatigue from exertion.

Correct answer: Dizziness and palpitations.

Cardiac arrhythmias disrupt the heart's normal pumping efficiency, leading to reduced blood flow to the brain and body. This decreased perfusion often manifests as dizziness due to inadequate cerebral blood supply. Palpitations, or the sensation of a racing, pounding, or skipped heartbeat, are a direct result of the irregular electrical activity within the heart itself.

Question 4: What is the function of the coronary arteries?

• Supply blood to the lungs.
• Supply blood to the heart muscle. (Correct answer)
• Connect the atria to the ventricles.
• Drain deoxygenated blood from the heart.

Correct answer: Supply blood to the heart muscle.

The coronary arteries are vital blood vessels that branch off the aorta and encircle the heart. Their primary function is to deliver oxygen-rich blood and essential nutrients directly to the heart muscle (myocardium). This continuous supply is crucial for the heart to maintain its tireless pumping action and overall function.

Question 5: Which blood vessel carries deoxygenated blood from the heart to the lungs?

• Pulmonary vein.
• Aorta.
• Pulmonary artery. (Correct answer)
• Inferior vena cava.

Correct answer: Pulmonary artery.

The pulmonary artery is unique among arteries because it carries deoxygenated blood. It originates from the right ventricle of the heart and transports this blood to the lungs. In the lungs, the blood releases carbon dioxide and picks up oxygen, becoming oxygenated before returning to the heart via the pulmonary veins.

Question 6: What is the role of the atrioventricular (AV) node?

• Delays the electrical impulse between atria and ventricles. (Correct answer)
• Regulates blood flow.
• Initiates the heart's electrical activity.
• Supplies oxygenated blood to the heart.

Correct answer: Delays the electrical impulse between atria and ventricles.

The atrioventricular (AV) node is a critical component of the heart's electrical conduction system. Its main role is to delay the electrical impulse received from the atria before it passes to the ventricles. This brief delay ensures that the atria have sufficient time to fully contract and empty their blood into the ventricles before ventricular contraction begins, optimizing cardiac efficiency.

Question 7: What does the term 'cardiac output' refer to?

• The total volume of blood in the arteries.
• The volume of blood pumped by the heart per minute. (Correct answer)
• The heart rate per minute.
• The pressure exerted by the blood in the veins.

Correct answer: The volume of blood pumped by the heart per minute.

Cardiac output is a fundamental measure of the heart's performance. It quantifies the total volume of blood that the heart pumps into the systemic circulation each minute. This value is calculated by multiplying the heart rate (beats per minute) by the stroke volume (volume of blood pumped per beat), reflecting the heart's ability to meet the body's circulatory demands.

Question 8: Which part of the heart is primarily responsible for the oxygenation of blood?

• Right atrium.
• Right ventricle.
• Left atrium.
• Left ventricle. (Correct answer)

Correct answer: Left ventricle.

While oxygenation of blood occurs in the lungs, the left ventricle is primarily responsible for pumping the *oxygenated* blood to the entire body. After receiving oxygen-rich blood from the left atrium, the left ventricle contracts powerfully. This strong contraction generates the high pressure needed to propel blood through the aorta and into the systemic circulation, delivering oxygen and nutrients to all tissues.

Question 9: What is the primary cause of coronary artery disease?

• Infection.
• Plaque buildup in the arteries. (Correct answer)
• High blood pressure.
• Genetic predisposition.

Correct answer: Plaque buildup in the arteries.

Coronary artery disease (CAD) is predominantly caused by atherosclerosis, which involves the buildup of fatty deposits, cholesterol, and other substances, collectively known as plaque, within the coronary arteries. This plaque accumulation narrows the arteries, reducing blood flow to the heart muscle. Over time, this can lead to symptoms like angina or even a heart attack if blood flow is severely restricted or blocked.