Myasthenia gravis is an autoimmune disorder in which autoantibodies bind to cholinergic receptors on muscle cells and impairs the ability of the neurotransmitter acetylcholine to induce muscular contraction. This leads to fatigue, weakening and paralysis of skeletal muscles of mouth and throat which may prevent normal swallowing. Gout arthritis is caused due to excessive formation of uric acid. It gets deposited in synovial joints and causes inflammation. Ostcoporosis is a discase in which bone loses minerals and fibres from its matrix. Muscular dystrophy is inborn abnormality of muscles associated with dysfunction and ultimately with deterioration. Related Theory Autoimmune diseases are a group of disorders in which tissue injury is caused by humoral (autoantibodies) or cell-mediated (by autoreactive T cells) immune response to self-antigens.