Name two systems that regulate various functions in the body.

Explanation

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for two systems that regulate various functions in the body.

2. **Recognize the Systems**: The two primary systems that regulate body functions are:
- **Endocrine System**: This system is responsible for hormone production and secretion. It consists of various glands that release hormones into the bloodstream, which then travel to different tissues to regulate bodily functions.
- **Nervous System**: This system controls both voluntary and involuntary actions by sending signals throughout the body. It enables communication between different parts of the body to coordinate functions.

...