Regarding the valves of the human heart, which of the following statements is correct?

Introduction / Context:
The human heart contains four main valves that ensure one way flow of blood through its chambers and into the great arteries. Understanding the correct positions and functions of these valves is crucial for learning cardiovascular anatomy and physiology. This question asks you to pick the one correct statement from several descriptions about heart valves and their roles.

Given Data / Assumptions:

Options mention aortic, pulmonary, atrioventricular, tricuspid and mitral valves, as well as chordae tendineae and semilunar valves. We are asked to identify which statement accurately describes normal human heart anatomy and function. We assume a standard four chambered heart with two atria, two ventricles and four principal valves. Statements involve both location and role of the valves.

Concept / Approach:
The two atrioventricular (AV) valves are the tricuspid valve on the right side and the mitral (bicuspid) valve on the left side. They lie between atria and ventricles. These valves are attached to papillary muscles inside the ventricles by fibrous cords called chordae tendineae. During ventricular contraction, the chordae tendineae prevent the valve leaflets from inverting back into the atria and thereby reduce regurgitation of blood. The aortic and pulmonary valves are semilunar valves that control blood flow out of the heart into the aorta and pulmonary artery, not into the heart chambers. The tricuspid valve is between the right atrium and right ventricle, and the mitral valve is between the left atrium and left ventricle, not on the right side.

Step-by-Step Solution:
Step 1: Evaluate option a, which says aortic and pulmonary valves control blood flow into the heart. This is incorrect; they control flow out of the heart from the ventricles into arteries. Step 2: Examine option b, which states that AV valves are supported by chordae tendineae to prevent regurgitation into the atria during ventricular contraction. This is a standard textbook description and is correct. Step 3: Check option c, which incorrectly places the tricuspid valve between the left atrium and left ventricle; in reality, it is between the right atrium and right ventricle. Step 4: Check option d, which incorrectly claims the mitral valve separates the right atrium from the right ventricle; actually, the mitral valve lies between the left atrium and left ventricle. Step 5: Evaluate option e, which incorrectly positions semilunar valves between atria and ventricles, whereas they are at the exits of the ventricles into the aorta and pulmonary artery.

Verification / Alternative check:
A simple verification method is to recall a labelled diagram of the heart. You will see the tricuspid valve on the right side and the mitral valve on the left side, both with chordae tendineae attaching their leaflets to papillary muscles. When the ventricles contract, these cords keep the valves from flipping backward. The semilunar valves sit at the base of the aorta and pulmonary artery and open only when ventricular pressure exceeds arterial pressure. Since only option b correctly captures this anatomical and functional detail, it must be the correct statement.

Why Other Options Are Wrong:
Option a reverses the direction of control; aortic and pulmonary valves regulate blood leaving, not entering, the heart. Option c misplaces the tricuspid valve; it belongs to the right side, not the left. Option d misplaces the mitral valve; it is on the left side, not between the right atrium and ventricle. Option e incorrectly locates semilunar valves between atria and ventricles, whereas atrioventricular valves occupy that position. Each of these errors conflicts with established heart anatomy.

Common Pitfalls:
Students often mix up right and left side valves or confuse the names tricuspid and bicuspid (mitral). Another frequent confusion is between atrioventricular valves and semilunar valves. To avoid these mistakes, remember a simple association: tricuspid right, bicuspid left, both with chordae tendineae; semilunar valves guard the exits into the aorta and pulmonary artery. Keeping this mental map in mind will help you quickly identify correct statements about heart valves in exams.

Final Answer:
The correct statement about heart valves is that the atrioventricular (AV) valves are supported by chordae tendineae, which help prevent regurgitation of blood into the atria during ventricular contraction.