Smooth muscles are also known as involuntary muscles, meaning that a person cannot physically chose to move them. Instead, smooth muscles are controlled in the background by brain and body. An example of smooth muscle is the digestive system, where muscles in the contract to squeeze food down to the stomach or tighten when you have an illness so that you are sick. Other examples of smooth muscle include the bladder and the muscle behind the eyes that keeps your eyes focused. Smooth muscles are also found in the blood vessels, helping blood to move around the body.
Cardiac muscle is in your heart, also known as myocardium. Like smooth muscle, cardiac muscle is an involuntary muscle. These muscles are thick because they have to contract frequently to move blood in and out of the heart.
Skeletal muscles are the muscles that allow you to control the movements of your body, arms and legs, etc. These muscles are attached to your bones via tendons, which are like cords made of tissue. In order for you to move, your skeletal muscles, tendons and bones must all work together. Skeletal muscles come in different shapes and sizes – just compare the muscles of a weight lifter to your own!.
Other skeletal muscles in the body you may not be as aware of include those in the neck or face. Even your tongue contains skeletal muscles. Skeletal muscles often work in pairs, such as the biceps, which bend the arms, which work with the triceps, which straighten the arms.
In the video when the biceps contract the arm bends, when the triceps contract it straightens out again…