Which of the following statement is correct ?

Options

A. Some tranquillisers function by inhibiting the enzymes which catalyse the degradation of noradrenaline
B. Tranquilisers are narcotic drugs .
C. Tranquilisers are chemical compounds that do not effect the message transfer from nerve to receptor.
D. Tanquilisers are chemical compounds that can relieve pain and fever .

Answer

To determine which statement is correct regarding tranquilizers and their functions, let's analyze the statements step by step.

### Step-by-Step Solution:

1. **Understanding Tranquilizers**:
- Tranquilizers are medications that help to calm the brain and slow down its activity. They are often used to treat anxiety and other related conditions.

2. **Analyzing the First Statement**:
- The first statement claims that some tranquilizers function by inhibiting the enzymes that catalyze the degradation of noradrenaline.
- Noradrenaline (also known as norepinephrine) is a neurotransmitter that plays a crucial role in the nervous system. By inhibiting its degradation, tranquilizers can increase its levels, which can help in calming the nervous system.
- This statement is **correct**.

3. **Analyzing the Second Statement**:
- The second statement suggests that tranquilizers are chemical compounds that do not affect the message transfer from the nervous system to the receptors.
- However, tranquilizers do affect the transmission of signals in the nervous system, as they work on the central nervous system to help manage anxiety and stress. Thus, this statement is **incorrect**.

4. **Analyzing the Third Statement**:
- The third statement claims that tranquilizers are chemical compounds that relieve pain and fever.
- Pain relievers are known as analgesics, and fever reducers are called antipyretics. Tranquilizers do not fall into these categories, making this statement **incorrect**.

5. **Conclusion**:
- After analyzing all the statements, the only correct statement is the first one, which states that some tranquilizers function by inhibiting the enzymes that catalyze the degradation of noradrenaline.

### Final Answer:
The correct statement is: **Some tranquilizers function by inhibiting the enzymes which catalyze the degradation of noradrenaline.**

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