The basic architecture of the human body relies on 206 bones, over 600
muscles, and a complex assortment of other tissues - ligaments, tendons, and
cartilage - that enable the body to move with remarkable efficiency.
What can go wrong
Although tough, these structures often suffer damage. Muscles, tendons, and
ligaments can be -trained or torn by violent movement, which may cause
inflammation, making the affected tissue swollen and painful. Joints, especially
those that bear the body's weight - hips, knees, ankles, and vertebrae - are
prone to wear and tear. The cartilage covering the bone ends may tear, causing
pain and inflammation. Joint damage also occurs in rheumatoid arthritis, which
is thought to be a form of autoimmune disorder. Gout, in which uric acid
crystals form in some joints, may also cause inflammation, a condition known as
gouty arthritis. Another problem affecting the muscles and joints includes nerve
injury or degeneration, which alters nerve control over muscle contraction.
Myasthenia gravis, in which transmission of signals between nerves and muscles
is reduced, affects muscle control as a result. Bones may also be weakened by
vitamin, mineral, or hormone deficiencies.
Why drugs are used
A simple analgesic drug or one that has an anti-anti-inflammatory effect will
provide pain relief in most of the above conditions. For severe inflammation, a
doctor may inject a drug with a more powerful anti-inflammatory effect, such as
a corticosteroid, into the affected site. In cases of severe progressive
rheumatoid arthritis, antirheumatic drugs may halt the disease's progression and
relieve symptoms.
Drugs that help to eliminate excess uric acid from the body are often prescribed
to treat gout. Muscle relaxants that inhibit transmission of nerve signals to
the muscles are used to treat muscle spasm. Drugs that increase nervous
stimulation of the muscle are prescribed for myasthenia gravis. Bone disorders
in which the mineral content of the bone is reduced are treated with supplements
of minerals, vitamins, and hormones.
Muscles that control body movement are attached to the bone by tendons.
Bones act as levers, which are worked by muscles: when the muscle contracts,
movement occurs at the joint.
Joints are held together by bands of tough fibrous tissue known as ligaments.
Friction between the ends of two bones is reduced by the cartilage that covers
each bone end.
Muscle
Each muscle is made of thick bundles of fibres: each bundle in turn is made of
fibrils. Tiny nerves and blood vessels enable the muscle to function.
Bone
Long bones, such as the femur, contain a network of longitudinal and transverse
canals to carry blood, nerves, and lymph vessels through the bone.
Major Drug Groups
Non-steroidal anti-inflammatory drugs
Antirheumatic drugs
Locally acting corticosteroids
Drug for gout
Muscle-relaxant drugs
Drugs used for myasthenia gravis
Drugs for bone disorders
