Human Muscular System

The human muscular system is made up of over 600 muscles, which act in groups. Muscles, in turn, are made up of fibers and cells. Muscles are what enable you to do just about everything – from walking to lifting heavy objects to helping to pump blood throughout the body. Muscles are distinguished as either involuntary or voluntary. Involuntary muscles function within the body automatically, without you being able to control them. Voluntary muscles are the ones that are under your control.

All muscles are made up of the same type of material – a kind of an elastic tissue, akin to what rubber bands are made of. Each muscle is made up of thousands of tiny fibers. There are three kinds of muscles in the human muscular system: the skeletal muscle; the cardiac muscle; and the smooth muscle. Plus, the facial muscles and the tongue are a unique kind by themselves.

The Skeletal Muscles: These are the voluntary type of muscles in the human muscular system. This means that they can be controlled by you. For example, you cannot pick up that mug of coffee with your hand unless you want your hand to do so. They are referred sometimes as striated muscles, because the dark and light fibrous material make them seem striped. These are also known as the musculoskeletal system, or the combination of the muscles and the bones that make up the skeleton.

Generally, skeletal muscles are attached to the ends of bones, stretching all across the joint and then attached once more to another bone. Tendons, which are cords or bands of inelastic tissue, are what attach the muscles to the bones. Skeletal muscles are of different shapes and sizes, which enable them to perform a variety of tasks. The gluteus maximus, or the muscle that occurs in the buttocks, is the largest skeletal muscle in the human muscular system. Some of the other major skeletal muscles are the deltoid muscle in the shoulders, the biceps and triceps in the arm, the pectoralis in the chest, the rectus abdominus in the abdomen, the quadriceps and the hamstring muscles in the legs.

The Cardiac Muscle: The heart is made up of the cardiac muscle, which is also referred to as the myocardium. These muscles are thick and contract in order to pump out the blood and then relax in order to allow more blood in. The cardiac muscle is an involuntary muscle, or the type that works without your volition. Special type of cells in the cardiac muscle, called the pacemaker, help in controlling the heartbeat.

The Smooth Muscles: These are the involuntary muscles of the human muscular system, and they generally occur in layers or sheets, with one muscle layer behind another. These muscles are not under your control. The brain and the body control these muscles in performing their functions without any conscious volition from your part.

Some of the examples of smooth muscles are the stomach and the digestive system, which contract and relax in order to pass food through the alimentary canal of the body. The bladder is another example of smooth muscle, and so is the uterus in women. Smooth muscles also occur in the eyes, which help to keep the eyes focused. According to scientists, the eyes can move over 100,000 times in a day, making them the busiest muscles in the human muscular system.

The Facial Muscles: There are more than 30 muscles in the face. Not all of the facial muscles are attached to bones, as is the case in the other parts of the body. Many of the facial muscles are attached to the underside of facial skin. The contractions of these muscles are what give the face its various expressions, such as frowning, laughter, surprise, sadness and so on.

The Tongue: And another unique muscle is the tongue, which is free at one end and only attached on the other end. The tongue actually comprises of a group of muscles, which work in unison, enabling you to chew and swallow food, and talk.