Human Muscle Reference

myminifactory

The human body's muscular system is comprised of three major categories: skeletal muscle, cardiac muscle, and smooth muscle. Skeletal muscle is attached to bones by tendons and is responsible for voluntary movements such as walking, running, and lifting. This type of muscle is striated in appearance due to the presence of sarcomeres, which are highly organized bundles of myofibrils that contain actin and myosin filaments. Cardiac muscle is found exclusively in the heart and plays a crucial role in pumping blood throughout the body. It is also striated but has distinct characteristics that set it apart from skeletal muscle, such as an irregular heartbeat and involuntary contractions. Smooth muscle is found within the walls of various organs including the digestive tract, airways, and blood vessels. Its primary function is to facilitate the movement of substances through these structures, often in a rhythmic or peristaltic manner.