Trivia: What is NOT a category within the muscular system?
Smooth
Cardiac
Skeletal
Lymphatic
Correct Answer: Lymphatic
So why is this answer correct? : The muscular system can be broken down into three subsystems: skeletal, smooth, and cardiac muscles. Skeletal muscles are attached to bones and are responsible for bodily movements. Smooth muscles are found in the walls of hollow organs, such as the intestines, uterus, and stomach. Cardiac muscles are the smallest muscle group, located in the heart’s walls and responsible for keeping it pumping.