Rapid integration of the functional activities in human is acheieved by :

Options

A. Nervous system
B. Endocrine system
C. Blood
D. Muscular system

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which system in the human body is responsible for the rapid integration of functional activities. The options provided are the nervous system, endocrine system, blood, or muscular system.

2. **Identifying the Systems**:
- The **nervous system** is responsible for controlling many functions of the body and mind by processing information quickly.
- The **endocrine system** releases hormones that travel through the bloodstream to target cells, but this process is slower compared to the nervous system.
- **Blood** is a transport medium and does not directly integrate functional activities.
- The **muscular system** responds to signals from the nervous system but does not integrate activities on its own.

3. **Analyzing the Nervous System**: The nervous system uses sensory receptors to gather information from the environment. This information is sent to the Central Nervous System (CNS) where it is processed rapidly. The CNS then sends out signals to muscles and glands to initiate a response.

4. **Speed of Response**: The nervous system can respond almost instantaneously to stimuli. For example, if you touch something hot, the nervous system quickly processes this information and sends a signal to retract your hand, demonstrating rapid integration.

5. **Comparing with the Endocrine System**: The endocrine system, while important for long-term regulation and slower responses, takes more time to synthesize hormones and transport them to target cells. This makes it less suitable for rapid integration compared to the nervous system.

6. **Conclusion**: Given the rapid processing and response capabilities of the nervous system compared to the slower endocrine system, the correct answer to the question is the **nervous system**.

**Final Answer**: The rapid integration of functional activities in humans is achieved by the **nervous system**.

---