Read the following statements and select the correct ones
(i) Nodal tissue is specialised cardiac musculature in human heart which has the ability to generate action potential due to an external stimuli
(ii) Position of SAN - right corner of right atrium
(iii) Position of AVN - right corner of ventricle
(iv) AV bundle continues from AVN
(v) Purkinje fibres are modified cardiac muscle fibres that originate from the atrioventricular node and spread into the two ventricles.

Options

A. (i) and (ii)
B. (i) and (iii)
C. (ii),(iv) and (v)
D. all of these

Explanation

To determine which statements about the nodal tissue and its components in the human heart are correct, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (i)**: "Nodal tissue is specialised cardiac musculature in human heart which has the ability to generate action potential due to an external stimuli."
- **Analysis**: This statement is incorrect. Nodal tissue, including the sinoatrial node (SAN) and atrioventricular node (AVN), can generate action potentials intrinsically without needing external stimuli.
- **Conclusion**: **Incorrect**

2. **Statement (ii)**: "Position of SAN - right corner of right atrium."
- **Analysis**: This statement is correct. The sinoatrial node (SAN) is located in the upper wall of the right atrium, often referred to as the pacemaker of the heart.
- **Conclusion**: **Correct**

3. **Statement (iii)**: "Position of AVN - right corner of ventricle."
- **Analysis**: This statement is incorrect. The atrioventricular node (AVN) is located at the junction of the atria and ventricles, specifically in the lower part of the right atrium, not in the ventricle.
- **Conclusion**: **Incorrect**

4. **Statement (iv)**: "AV bundle continues from AVN."
- **Analysis**: This statement is correct. The AV bundle, also known as the bundle of His, originates from the atrioventricular node (AVN) and extends into the ventricles.
- **Conclusion**: **Correct**

5. **Statement (v)**: "Purkinje fibres are modified cardiac muscle fibres that originate from the atrioventricular node and spread into the two ventricles."
- **Analysis**: This statement is partially misleading. Purkinje fibers do arise from the conduction system that includes the AV bundle, which itself originates from the AVN, and they spread throughout the ventricles. However, they do not directly originate from the AVN.
- **Conclusion**: **Correct in essence but requires clarification** (for the sake of this question, we will consider it correct).

### Final Assessment:
The correct statements are:
- Statement (ii): Correct
- Statement (iv): Correct
- Statement (v): Correct (with clarification)

Thus, the correct statements are 2, 4, and 5.

### Answer:
The correct statements are: **(ii), (iv), and (v)**.