Human Muscle Structure
The human muscle system is a complex network that plays a crucial role in movement, posture, and balance. It is broadly divided into three types: skeletal muscle, smooth muscle, and cardiac muscle.
1. Skeletal Muscle: These muscles are attached to the bones by tendons and are responsible for creating movement in the body. There are more than 600 skeletal muscles, making up about 40 percent of a person’s body weight. Each skeletal muscle is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves. When the nervous system signals the muscle to contract, groups of muscles work together to move the skeleton.
2. Smooth Muscle: Found in the walls of hollow organs, respiratory passageways, and blood vessels, smooth muscle is under involuntary control. Its wavelike movements propel things through the bodily system, such as food through your stomach or urine through your bladder.
3. Cardiac Muscle: This type of muscle makes up the walls of the heart and is responsible for the rhythmic contractions of that vital pumping organ. It is under involuntary control and creates the steady, rhythmic pulsing that pumps blood through the body.
A muscle consists of fibers of muscle cells surrounded by protective tissue, bundled together many more fibers, all surrounded in a thick protective tissue. Each fiber comprises many tiny strands called fibrils. Muscle movement happens when neurological signals produce electrical changes in muscle cells. During this process, calcium
