Parasympathetic stimulation causes vasodilatation in penis by release of :-

Options

A. A-Ch
B. Nitric oxide
C. Epinephrine
D. Nor epinephrin

Answer

**Step-by-Step Solution:**

1. **Understanding Vasodilation**: Vasodilation refers to the widening of blood vessels, which allows increased blood flow. In the context of the penis, this is crucial for achieving an erection.

2. **Role of the Parasympathetic Nervous System**: The parasympathetic nervous system is part of the autonomic nervous system and is responsible for stimulating bodily functions that occur when at rest. It plays a key role in sexual arousal and erection.

3. **Chemical Mediators**: During parasympathetic stimulation, certain chemicals are released that facilitate vasodilation. The primary chemicals involved in this process include Acetylcholine (ACH) and Nitric Oxide (NO).

4. **Acetylcholine (ACH)**: While ACH is involved in various bodily functions, including muscle contraction and glandular secretion, it is not the primary mediator responsible for vasodilation in the penis.

5. **Nitric Oxide (NO)**: Nitric Oxide is a crucial signaling molecule that directly causes vasodilation. It relaxes the smooth muscles in the blood vessels of the penis, leading to increased blood flow and erection.

6. **Conclusion**: The correct answer to the question is that parasympathetic stimulation causes vasodilation in the penis primarily through the release of Nitric Oxide.

**Final Answer**: Nitric Oxide

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