Multiple sclerosis primarily affects which part of the body?

Multiple sclerosis primarily affects the central nervous system, which comprises the brain and spinal cord. This disease is characterized by the immune system mistakenly attacking the protective myelin sheath that covers nerve fibers, leading to communication problems between the brain and the rest of the body. Symptoms can vary widely but often include issues with muscle control, vision, balance, and feeling, among others.

Understanding that multiple sclerosis targets the central nervous system helps in recognizing its neurological implications, such as cognitive changes or physical disabilities. The other body systems listed, such as the circulatory, respiratory, and digestive systems, are not the primary targets of multiple sclerosis, which is why they do not fit the question regarding the effects of this condition.