Sympathetic and parasympathetic nervous systems are often synergistic in their functions.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Terms**: First, we need to clarify what is meant by "synergistic." The term "synergistic" refers to two systems or processes that work together in coordination to achieve a common goal.

2. **Identifying the Nervous Systems**: The autonomic nervous system (ANS) is divided into two main parts: the sympathetic nervous system and the parasympathetic nervous system.

3. **Functions of the Sympathetic Nervous System**: The sympathetic nervous system is primarily responsible for the "fight or flight" response. This means it activates the body to respond to perceived threats, increasing heart rate, dilating pupils, and redirecting blood flow to essential muscles.

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