Human Muscle Structure
The human muscle system is a complex network of tissues designed to provide movement and maintain posture. 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 under voluntary control. They create movement in the body. There are more than 600 skeletal muscles, making up about 40 percent of a persons body weight. Each skeletal muscle is a discrete organ constructed of 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, impulses from nerve cells control the contraction of each muscle fiber.
Muscle movement happens when neurological signals produce electrical changes in muscle cells. During this process, calcium is released into the cells and brings about a short muscle twitch. Problems with the junction between the cells called a synapse can lead to neuromuscular diseases.
Proper nutrition and exercise are important to keeping all muscles healthy, whether they are cardiac, smooth, or skeletal. Some muscular disorders and conditions that affect muscles include muscle pain, sprains and strains, bruising, cramping, myopathy, muscular dystrophy, Parkinsons disease, fibromyalgia, and multiple sclerosis.
In conclusion, the human muscle system is a marvel of biological engineering, enabling us to perform a vast range of movements and tasks. It is a complex system that requires proper care and nutrition to function optimally.
