Muscle is an elastic type tissue made up of fibers that contract. This contraction is what creates movement, be it a body part or substance.
Muscles are essentially of three types based on their structure, function and location. The muscle types are skeletal, cardiac and smooth.
Skeletal muscle type moves the body and is under your control. They maintain your posture and are the muscles that move you and other stuff around.
The cardiac type is only in your heart and is not generally under your control. This thick muscle type has a single purpose, to move the substance of blood via its contraction and relaxation.
Smooth muscles are distributed throughout your body and act without awareness nor voluntary control. Their primary task is to propel substances through passageways, like your lungs, digestive tract, urinary tract and circulatory system.
Movement is accomplished through muscle contraction. Contracting a muscle basically means shortening it, which can occur in an instant. A contraction involves a highly complex series of chemical events and a large amount of energy in the form of ATP.
Repetitive use or maximum effort can lead to muscle fatigue, both limiting the force of contraction. And conditioning or growth of a muscle can stave off fatigue, therefore allowing for increase in a muscle contraction endurance or strength.
A muscle disease can affect a muscle in various ways. Just some of the muscle diseases or diseases that have some affect on muscles are:
- polio
- myositis
- myopathy
- fibromyalgia
- rhabdomyolysis
- muscle infection
- myasthenia gravis
- rhabdomyosarcoma
- muscular dystrophy
- compartment syndrome
- chronic fatigue syndrome
Other diseases can affect muscles ability to function as well, such as certain autoimmune diseases, metabolic diseases, inflammatory diseases and neurological or neuromuscular disorders.
The consequence of a muscle disease typically reduces its ability to contract, causing symptoms of myalgia and muscle weakness. Although, it could ultimately cause a muscle to completely lose its functional capability, causing paralysis.
