Which of the following two systems are opposite in action to each other?

Options

A. Nervous -Sensory
B. Nervous -Endocrine
C. Sensory -Endocrine
D. Parasympathetic -Sympathetic

Answer

To determine which two systems are opposite in action to each other, we will analyze the options provided.

### Step-by-Step Solution:

1. **Identify the Systems in Each Option**:
- The question presents several systems. We need to evaluate each pair to see if they function oppositely.

2. **Evaluate the Nervous Sensory System**:
- The Nervous Sensory System detects and encodes stimuli. It works by sending signals to the central nervous system, which processes these signals. This system does not exhibit opposite actions; rather, it works in coordination.

3. **Evaluate the Nervous and Endocrine System**:
- The Nervous and Endocrine systems work together to maintain homeostasis, development, and reproduction. They complement each other rather than oppose each other.

4. **Evaluate the Sensory Endocrine System**:
- Similar to the previous systems, the Sensory Endocrine system also works in conjunction, controlling movements and other functions together.

5. **Evaluate the Parasympathetic and Sympathetic Systems**:
- These two systems are part of the autonomic nervous system. The Sympathetic system is responsible for the "fight or flight" response, which prepares the body for quick action in emergencies. In contrast, the Parasympathetic system is known as the "rest and digest" system, which promotes relaxation and digestion. These two systems have antagonistic functions; when one is activated, the other is inhibited.

6. **Conclusion**:
- Based on the evaluations, the Parasympathetic and Sympathetic systems are opposite in action to each other. Therefore, the correct answer is **option 4: Parasympathetic and Sympathetic**.