Which part of our central neural system acts as a master clock ?

Explanation

**Step-by-Step Solution:**

1. **Identify the Central Nervous System (CNS)**: The central nervous system consists of the brain and spinal cord. It is responsible for processing and transmitting information throughout the body.

2. **Determine the Role of the Brain**: Within the brain, various parts have specific functions. We need to identify which part regulates body rhythms.

3. **Focus on the Hypothalamus**: The hypothalamus is a small region of the brain that plays a crucial role in many bodily functions, including the regulation of hormones, temperature, and circadian rhythms.

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