Question

Thebesian valve guards the opening of ___________.

• A. Coronary sinus
• B. Superior vena cava
• C. Coronary artery
• D. Pulmonary vein

Hint:

The Thebesian valve is also known as the valve of the coronary sinus.

Answer 1

The Correct Option is A

Step 1: Understanding the Thebesian valve.
The Thebesian valve is a small semilunar valve present in the right atrium of the human heart. Its main function is to regulate blood flow entering the right atrium.
Step 2: Anatomical location.
The coronary sinus collects deoxygenated blood from the myocardium (heart muscles) and opens into the right atrium. The Thebesian valve guards the opening of the coronary sinus and prevents backflow of blood during atrial contraction.
Step 3: Analysis of options.
(A) Coronary sinus: Correct, as the Thebesian valve is specifically associated with its opening.
(B) Superior vena cava: It opens directly into the right atrium without a valve.
(C) Coronary artery: Arteries are not guarded by valves at their origin in the atrium.
(D) Pulmonary vein: These veins open into the left atrium and are unrelated to the Thebesian valve.
Step 4: Conclusion.
The Thebesian valve guards the opening of the coronary sinus.