Muscle

There are three main types of muscles in the body: skeletal, smooth, and cardiac.

Skeletal muscle: These are the muscles that are attached to the skeleton and are responsible for voluntary movement. They are also known as striated muscles because of their striped appearance under a microscope.

Smooth muscle: These muscles are found in the walls of organs and blood vessels, and are responsible for involuntary movement. They are also known as non-striated muscles because they do not have the same striped appearance as skeletal muscles.

Cardiac muscle: This muscle is found in the heart and is responsible for pumping blood throughout the body. Cardiac muscle is involuntary and striated.

All these muscles are controlled by the nervous system, but the cardiac muscle has its own electrical system that coordinates the contraction, allowing the heart to beat independently of the brain.

What do muscles do?

Muscles perform a variety of functions in the body, including movement, posture, and stability.

-Movement: Muscles produce movement by contracting and relaxing. Skeletal muscles, in particular, are responsible for the movement of the limbs and other parts of the body. These muscles work in pairs, with one contracting while the other relaxes, to produce smooth, coordinated movement.

-Posture: Muscles also help to maintain posture by keeping the body in a particular position. They work to keep the spine in an upright position and to hold the head, arms, and legs in place.

-Stability: Muscles also provide stability to joints and help to protect them from injury. The muscles around a joint will contract to prevent excessive movement and keep the joint stable.

-Respiration: Muscles in the diaphragm and intercostal muscles play a vital role in breathing, which is essential for life.

-Digestion: The smooth muscles in the wall of the gastrointestinal tract contract and relax to move food through the digestive system.

-Circulation: Cardiac muscle contractions pump blood throughout the body, which is essential for the delivery of oxygen and nutrients to the body's cells.

-Temperature regulation: Muscles are also involved in regulating body temperature through the process of thermogenesis, which is the production of heat.

-Hormone regulation: The muscles play a role in regulating the levels of certain hormones in the blood. For example, exercise can increase the production of endorphins which can improve mood and reduce stress.

What conditions and disorders affect the muscles?

There are a variety of conditions and disorders that can affect muscles, including:

-Muscular dystrophy: A group of genetic disorders that cause muscle weakness and degeneration.

-Myositis: An inflammation of the muscles that can cause pain, weakness, and muscle wasting.

-Fibromyalgia: A chronic condition that causes muscle pain and tenderness, as well as fatigue and sleep disturbances.

-Myasthenia gravis: An autoimmune disorder that causes muscle weakness and fatigue.

-Polymyositis: A chronic inflammatory disorder that causes muscle weakness, particularly in the muscles of the neck, shoulders, hips, and proximal extremities.

-Rhabdomyolysis: A condition in which muscle breakdown leads to the release of muscle fibers into the bloodstream, which can lead to kidney damage.

-Myofascial pain syndrome: A chronic condition characterized by pain and tenderness in the muscles and associated connective tissue.

-Myotonic dystrophy: A genetic disorder that causes muscle weakness, stiffness, and myotonia (prolonged muscle contractions).

-Dermatomyositis: An inflammatory disorder that causes muscle weakness and a characteristic skin rash.

-Cramps: Sudden and involuntary muscle contractions that can cause pain and discomfort.

-Sprains and strains: Injuries that occur when a muscle or tendon is stretched or torn.

-Tension headaches: pain in the head, scalp, and neck caused by muscle tension.

These conditions and disorders can have various causes, including genetic factors, infections, injuries, and underlying medical conditions. Treatment options vary depending on the specific condition and may include physical therapy, medications, and in some cases surgery.