circuitry: electronic equipment consisting of a system of circuits
electronic equipment: equipment that involves the controlled conduction of electrons (especially in a gas or vacuum or semiconductor)
rheumatoid arthritis: a chronic autoimmune disease with inflammation of the joints and marked deformities; something (possibly a virus) triggers an attack on the synovium by the immune system, which releases cytokines that stimulate an inflammatory reaction that can lead to the destruction of all components of the joint