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 or function that is not associated with the bundle of His, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Bundle of His**:
- The bundle of His is a crucial part of the heart's electrical conduction system. It is responsible for transmitting electrical impulses from the atrioventricular (AV) node to the ventricles.

2. **Analyze the Options**:
- We have four statements to evaluate. We need to identify which one does not correctly describe the bundle of His.

3. **Evaluate Each Statement**:
- **Option A**: "Bundle of His carries cardiac impulse from AV node to ventricles."
- This statement is true. The bundle of His does carry impulses from the AV node to the ventricles.

- **Option B**: "These are modified muscle fibers that exhibit auto-excitability."
- This statement is also true. The bundle of His consists of modified muscle fibers that can generate electrical impulses on their own.

- **Option C**: "It is a bundle of neurons affecting heart rate."
- This statement is false. The bundle of His is not made up of neurons; it is made up of modified muscle fibers. Therefore, this option does not describe the bundle of His correctly.

- **Option D**: "It helps to spread impulses in ventricular musculature."
- This statement is true. The bundle of His does help in spreading electrical impulses throughout the ventricles, facilitating their contraction.

4. **Identify the Incorrect Statement**:
- After evaluating all options, we find that **Option C** is the feature that is not associated with the bundle of His.

### Final Answer:
The feature/function which is not associated with the bundle of His is **Option C: It is a bundle of neurons affecting heart rate.**

---