Which body system generates hea Integumentary Endocrine Skeletal Nervous Muscular

The body system that generates heat is the **Muscular** system. ### Explanation: - **Muscular System**: When muscles contract during physical activity, they produce heat as a byproduct of energy metabolism. This heat helps to maintain body temperature. - **Integumentary System**: This system includes the skin, hair, and nails, and primarily functions to protect the body and regulate temperature but does not generate heat. - **Endocrine System**: This system regulates bodily functions through hormones but does not directly generate heat. - **Skeletal System**: This system provides structure and support to the body but does not generate heat. - **Nervous System**: This system controls and coordinates body activities but does not generate heat. Thus, the correct answer is the **Muscular** system.