Which of the following body systems contribute to homeostasis?

Options

A. Digestive and excretory systems
B. Respiratory and nervous systems
C. Nervous and endocrine systems
D. Immune and cardiovascular systems

Explanation

To determine which body systems contribute to homeostasis, let's analyze the options provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding Homeostasis**:
- Homeostasis refers to the ability of the body to maintain a stable internal environment despite changes in external conditions. This includes regulating temperature, pH, hydration, and other vital conditions.

2. **Analyzing Each Option**:
- **Option 1: Digestive and Excretory Systems**:
- The digestive system is responsible for breaking down food and absorbing nutrients, while the excretory system removes waste products. Although both systems are essential for overall health, they do not primarily regulate homeostasis. Therefore, this option is incorrect.

- **Option 2: Respiratory and Nervous Systems**:
- The respiratory system facilitates gas exchange (oxygen and carbon dioxide) but does not directly maintain homeostasis. The nervous system does play a role in controlling and coordinating bodily functions. However, since the respiratory system alone does not contribute significantly to homeostasis, this option is also incorrect.

- **Option 3: Nervous and Endocrine Systems**:
- The nervous system is crucial for coordination and control of body functions, while the endocrine system regulates hormones that affect various bodily processes. Together, these systems form the neuroendocrine system, which is vital for maintaining homeostasis by responding to internal and external changes. This option is correct.

- **Option 4: Immune and Cardiovascular Systems**:
- The immune system protects against pathogens, and the cardiovascular system is responsible for circulating blood and nutrients. While both systems are important for health, they do not primarily focus on maintaining homeostasis. Thus, this option is incorrect.

3. **Conclusion**:
- The body systems that contribute to homeostasis are the **nervous and endocrine systems**. They work together to regulate the internal environment of the body effectively.

### Final Answer:
The correct answer is **Option 3: Nervous and Endocrine Systems**.