Mark the feature/function which is not associated with bundle of His?

Options

A. Carry cardiac impulses from AV node to ventricles
B. Modified muscle fibres, exhibits autoexcitability
C. It is bundle of neurons affecting heart rate
D. Helps to spread impulses in ventricular musculature

Answer

To solve the question regarding the feature/function not associated with the bundle of His, we can follow these steps:

### Step 1: Understand the Bundle of His
The bundle of His, also known as the atrioventricular bundle, is a collection of heart muscle cells specialized for electrical conduction. It plays a crucial role in the heart's conduction system, transmitting impulses from the atrioventricular (AV) node to the ventricles.

**Hint:** Recall the basic function of the bundle of His in the heart's electrical conduction system.

### Step 2: Analyze the Options
We need to evaluate the provided options to identify which one is not associated with the bundle of His.

1. **Carry cardiac impulses from the AV node to ventricles**: This is a primary function of the bundle of His, so this option is associated with it.

2. **Modified muscle fiber exhibits auto-excitability**: This statement is not true for the bundle of His. The auto-excitability is a feature of the sinoatrial (SA) node, not the bundle of His.

3. **Bundle of neurons affecting heart rate**: This option is misleading because while the bundle of His does play a role in heart rate through conduction, it is not primarily a bundle of neurons. However, it is still associated with the conduction of impulses.

4. **Helps to spread impulses in the ventricular musculature**: This is indeed a function of the bundle of His, as it helps to distribute electrical impulses throughout the ventricles.

### Step 3: Identify the Correct Answer
From the analysis, the option that is not associated with the bundle of His is **"modified muscle fiber exhibits auto-excitability."** This function is primarily associated with the SA node.

**Final Answer:** The feature/function not associated with the bundle of His is: **"modified muscle fiber exhibits auto-excitability."**