Question

Identify the option showing the correct labelling for p, q, r and s with reference to the conducting system of the human heart.

• A. p- Interventricular septum, q-AVN, r-Bundle of His, s-SAN
• B. p-SAN, q-AVN, r-Bundle of His, s-Interventricular septum
• C. p-AVN, q-SAN, r-Interventricular septum, s-Bundle of His
• D. p-Bundle of His, q-SAN, r-Interventricular septum, s-AVN

Answer 1

The Correct Option is B

Here is the solution for the question on the conducting system of the human heart:

Step 1: Understanding the Components of the Conducting System The conducting system of the heart includes specialized tissues responsible for the propagation of electrical impulses, which regulate heartbeats:

• SAN (Sinoatrial Node): The natural pacemaker of the heart, located in the right atrium.
• AVN (Atrioventricular Node): Located at the junction of the atria and ventricles, it delays the impulse before it passes to the ventricles.
• Bundle of His: A bundle of fibers that conducts the impulse from the AVN to the ventricles.
• Interventricular Septum: A wall between the two ventricles.

Step 2: Identify the Labels in the Diagram By referring to the structure of the heart's conducting system:

• P corresponds to the Interventricular septum.
• Q corresponds to the AVN.
• R corresponds to the Bundle of His.
• S corresponds to the SAN.

The correct answer is (B) : p-SAN, q-AVN, r-Bundle of His, s-Interventricular septum.

Answer 2

The correct answer is: (B) p-SAN, q-AVN, r-Bundle of His, s-Interventricular septum.

The diagram shows the conducting system of the human heart. Here's the explanation for each label:

• p - SAN (Sinoatrial Node): The SAN is located in the right atrium and is responsible for initiating the electrical impulses that regulate the heart's rhythm.
• q - AVN (Atrioventricular Node): The AVN is located between the atria and ventricles and is responsible for transmitting the electrical impulses from the atria to the ventricles, ensuring proper timing of contractions.
• r - Bundle of His: The Bundle of His is located along the interventricular septum and transmits the electrical impulses to the left and right ventricles.
• s - Interventricular septum: The interventricular septum is the wall that divides the left and right ventricles, through which the electrical impulses pass to the Bundle of His.

Thus, the correct labelling is p-SAN, q-AVN, r-Bundle of His, s-Interventricular septum.