The muscular system is a network of muscles that allows our bodies to move and perform various activities. It consists of three main types of muscles: skeletal muscles, which are attached to bones and help us move; smooth muscles, found in organs like the stomach; and cardiac muscle, which makes up the heart. Together, these muscles work to support our movements, maintain posture, and circulate blood. Muscles function by contracting and relaxing, which creates movement. When we decide to move, our nervous system sends signals to the skeletal muscles, causing them to contract. This process is essential for everyday activities, from walking and running to lifting objects and even smiling.