ECG Cardiac Anatomy

Question 1

Which chamber of the heart has the thickest muscular wall?

Accepted Answer

Left ventricle

Answer

The left ventricle has the thickest wall because it must generate enough pressure to pump blood throughout the entire systemic circulation.

Question 2

What is the normal pacemaker of the heart?

Accepted Answer

Sinoatrial (SA) node

Answer

The SA node, located in the right atrium, generates electrical impulses at 60-100 beats per minute and is the heart's natural pacemaker.

Question 3

Which valve separates the left atrium from the left ventricle?

Accepted Answer

Mitral valve

Answer

The mitral (bicuspid) valve has two leaflets and prevents backflow from the left ventricle into the left atrium during systole.

Question 4

What is the function of the coronary sinus?

Accepted Answer

Collects deoxygenated blood from cardiac veins

Answer

The coronary sinus is a large vein that collects deoxygenated blood from the cardiac veins and empties it into the right atrium.

Question 5

Which structure delays electrical impulses between the atria and ventricles?

Accepted Answer

AV node

Answer

The AV node provides a critical delay of about 0.1 seconds, allowing the atria to finish contracting before the ventricles begin.

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