Read the following statements (1 - V) and answer as asked next to them.
Statement - I : Nodal tissue is specialised Cardiac musculature in human heart has the ability to generate action potential due to an external stimuli.
Statement - II : Position of SAN - right corner of right atrium.
Statement - III : Position AVN – right corner of ventricle.
Statement - IV : AV bundle continues from AVN.
Statement - V : Purkinje fibers are modified cardiac muscle fibers that originate from the atrioventricular node and spread into the two ventricles.
How many of the above statements are correct?

Options

A. One
B. Two
C. Three
D. All

Answer

To determine how many of the statements regarding the nodal tissue and its components in the human heart are correct, we will analyze each statement one by one.

**Step 1: Analyze Statement I**
- **Statement I**: "Nodal tissue is specialized cardiac musculature in the human heart that has the ability to generate action potential due to an external stimuli."
- **Analysis**: This statement is incorrect. Nodal tissue, specifically the Sinoatrial Node (SAN) and Atrioventricular Node (AVN), has the ability to generate action potentials autonomously (auto-rhythmicity) without the need for external stimuli.

**Step 2: Analyze Statement II**
- **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, specifically at the right corner.

**Step 3: Analyze Statement III**
- **Statement III**: "Position 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 interatrial septum, not in the right corner of the ventricle.

**Step 4: Analyze Statement IV**
- **Statement IV**: "AV bundle continues from AVN."
- **Analysis**: This statement is correct. The Atrioventricular Bundle (Bundle of His) does indeed continue from the Atrioventricular Node (AVN) and conducts impulses into the ventricles.

**Step 5: Analyze Statement V**
- **Statement V**: "Purkinje fibers are modified cardiac muscle fibers that originate from the atrioventricular node and spread into the two ventricles."
- **Analysis**: This statement is incorrect. Purkinje fibers originate from the Bundle of His, which is a continuation of the AVN, not directly from the AVN itself.

**Conclusion**
- Correct Statements: II and IV
- Total Correct Statements: 2

**Final Answer**: 2 statements are correct.

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