The Structure, Function and Main Disorders of the Muscular System

The Muscular System - Structure and Function:

Comprised of around 600 individual muscles.
Divided into three types: skeletal (voluntary), smooth (involuntary), and cardiac.
Skeletal muscles are attached to bones and cause movement by contracting and relaxing. Physically seen under a microscope, they have a striped appearance, hence, often referred to as “striated muscles”.
Smooth muscles are found in the walls of organs and structures such as the esophagus, stomach, intestines, bronchi, uterus, ureters, blood vessels, and the arrector pili in the skin (responsible for goosebumps).
Cardiac muscle is a specialized muscle found only in the heart. It shares characteristics with both skeletal and smooth muscle.

Main Disorders of the Muscular System:

Muscular Dystrophy: A group of genetic disorders that cause progressive weakness and loss of muscle mass.
Myasthenia Gravis: A long-term condition causing muscle weakness which typically worsens after activity and improves after rest.
Fibromyalgia: A chronic disorder causing widespread musculoskeletal pain, fatigue, and tenderness in localized areas.
Myositis: An inflammation or swelling of the muscles, often caused by injury, infection, or an autoimmune disorder.
Sprains and Strains: Injuries to muscles or tendons due to physical activity. Differences exist - a sprain refers to stretching or tearing of ligaments, the tough bands of fibrous tissue that connect two bones together in your joints, whereas a strain refers to stretching or tearing of muscle or tendon, a fibrous cord of tissue that connects muscles to bones.
Rhabdomyolysis: A severe condition due to a direct or indirect muscle injury. It results from the death of muscle fibres and release of their contents into the bloodstream; this can lead to complications such as renal (kidney) failure.

To ensure optimal physical health, it’s important to understand the role of exercise and diet in maintaining muscular strength and endurance. Alongside this, an understanding of how injuries and disorders can impact the muscular system is required for appropriate prevention, treatment, and rehabilitation.