Muscular dystrophy is best described as:

• A. Progressive neurodegenerative disease of the spinal cord
• B. Progressive muscle weakness and degeneration of skeletal muscles
• C. Temporary muscle fatigue without structural change
• D. Inflammation of joints causing pain

Answer: (B)

The main concept tested is that muscular dystrophy is a condition where the muscles themselves progressively weaken and degenerate, not the nerves or joints. Muscular dystrophy describes inherited disorders in which skeletal muscle fibers deteriorate over time due to defects in the proteins that maintain their structure (for example, dystrophin in some forms). As contraction damages these already fragile fibers, they die and are replaced with fibrous or fatty tissue, leading to a steady loss of strength and function.

This is why the description that emphasizes progressive weakness with degeneration of skeletal muscles is the best fit. It’s not about a neurodegenerative process in the spinal cord, which would involve nerves rather than the muscle tissue itself. It isn’t simply temporary fatigue without structural change, since dystrophy involves actual degeneration of muscle fibers. And it isn’t joint inflammation, which characterizes arthritis rather than a muscular disease.