Which body system is primarily responsible for covering and shaping the body?

The muscular system is primarily responsible for covering and shaping the body, as it consists of all the muscles that facilitate movement and maintain posture. Muscles not only enable movement by contracting and relaxing but also contribute to the body's overall shape and structure. The muscular system works closely with the skeletal system, as muscles are attached to bones, allowing for coordinated movements. Additionally, the surface of muscles can significantly influence the body's contour and appearance, showcasing how integral this system is to both function and aesthetics.

In contrast, the nervous system focuses on transmitting signals and facilitating communication within the body, while the endocrine system regulates hormones that influence various bodily functions. The circulatory system is responsible for transporting blood and nutrients throughout the body, but it does not play a direct role in shaping or covering the body as the muscular system does.