Why do people need both the sympathetic and parasympathetic systems?

• A. To allow the body to function without any need for external stimuli.
• B. To maintain homeostasis by balancing the body's response to stress and relaxation.
• C. To ensure the body can only respond to stress effectively.
• D. To prevent the body from entering a state of rest.

Answer: (B)

Verified step by step guidance

1. Understand the role of the autonomic nervous system, which includes both the sympathetic and parasympathetic systems. These systems work together to regulate involuntary body functions such as heart rate, digestion, respiratory rate, and more.
2. Recognize that the sympathetic system is responsible for the 'fight or flight' response, preparing the body to respond to stress or danger by increasing heart rate, dilating airways, and mobilizing energy stores.
3. Learn that the parasympathetic system is often referred to as the 'rest and digest' system. It promotes relaxation and recovery by slowing the heart rate, increasing digestion, and conserving energy.
4. Explore the concept of homeostasis, which is the body's ability to maintain a stable internal environment despite external changes. Both systems are crucial for maintaining homeostasis by balancing responses to stress and relaxation.
5. Consider how the interplay between these systems allows the body to adapt to different situations, ensuring that it can respond to stress effectively while also being able to relax and recover when needed.