The two main variables in an experiment are the independent and dependent variable. An independent variable is the variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable. A dependent variable is the variable being tested and measured in a scientific experiment.
Medical Definition of RHEUMATOID ARTHRITIS. : a usually chronic disease that is considered an autoimmune disease and is characterized especially by pain, stiffness, inflammation, swelling, and sometimes destruction of jointsâabbreviation RA; called also atrophic arthritis; compare osteoarthritis.ull Definition of RHEUMATOID ARTHRITIS. : a usually chronic autoimmune disease that is characterized especially by pain, stiffness, inflammation, swelling, and sometimes destruction of joints. See rheumatoid arthritis defined for English-language learners. ADVERTISEMENT.
Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation of the joints. RA can be responsible for inflammation around the joints as well as in otherâ¦ organs and tissues of the body. An autoimmune disease is a condition where body's tissues are attacked by the body's own immune system.