Which of the following is not the action of sympathetic nervous system ?

Options

A. Slows down peristalsis
B. Erection of hair
C. Contraction in gall bladder
D. Constrict arteries and raises blood pressure

Answer

**Step-by-Step Solution:**

1. **Understanding the Sympathetic Nervous System (SNS)**:
- The sympathetic nervous system is a part of the autonomic nervous system (ANS) that prepares the body for 'fight or flight' responses. It generally increases physiological activities.

2. **Identifying Actions of the SNS**:
- Common actions of the sympathetic nervous system include:
- Dilation of pupils
- Increased heart rate
- Constriction of blood vessels (which raises blood pressure)
- Slowing down of peristalsis (the movement of the digestive tract)

3. **Evaluating the Given Options**:
- The options provided are:
- A. Slow down the peristalsis
- B. Erections of hair
- C. Contractions in gallbladder
- D. Constrict arteries and raises the blood pressure

4. **Analyzing Each Option**:
- **Option A (Slow down the peristalsis)**: This is an action of the SNS. It inhibits digestive processes.
- **Option B (Erections of hair)**: This is also an action of the SNS, causing piloerection (hair standing on end).
- **Option C (Contractions in gallbladder)**: This is NOT an action of the SNS. The SNS inhibits gallbladder contractions; the parasympathetic nervous system promotes gallbladder contractions.
- **Option D (Constrict arteries and raises the blood pressure)**: This is a typical action of the SNS.

5. **Conclusion**:
- The action that is NOT associated with the sympathetic nervous system is **C. Contractions in gallbladder**.

**Final Answer**: C. Contractions in gallbladder

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