The muscular system is a system of muscles that enable organisms to move their bodies, helps maintain posture, and helps keep the blood flowing throughout the body. Each animal, though, has its own unique muscular makeup that suit that animal's needs and environment. A human's muscular system consist of three types of muscles: Smooth, Cardiac, and Skeletal. Cardiac muscles make up and control the heart, skeletal muscle moves the body, and smooth muscles controls automatic movements like the stomach. Many other organisms, especially those in the same phylum as humans, Chordata, share these types of muscles. Without muscles, organisms would not be able to live. It is one of the most important parts of all organisms.