What does poliomyelitis primarily affect?

What does poliomyelitis primarily affect?

• A. The brain's white matter
• B. Gray matter of the spinal cord
• C. The peripheral nervous system
• D. The muscle tissues

Answer: (B)

Poliomyelitis primarily affects the gray matter of the spinal cord. This viral infection targets motor neurons in the anterior horn of the spinal cord, which is part of the central nervous system. The destruction of these motor neurons leads to muscle weakness and paralysis because the brain's signals to the muscles are disrupted. The term "poliomyelitis" itself derives from "poli-" meaning gray and "myelitis" meaning inflammation of the spinal cord, which highlights the focus on the gray matter. Understanding this distinction is important because identifying the correct anatomical focus of poliomyelitis aids in understanding the disease's impact and the resulting clinical manifestations, such as paralysis.

Poliomyelitis primarily affects the gray matter of the spinal cord. This viral infection targets motor neurons in the anterior horn of the spinal cord, which is part of the central nervous system. The destruction of these motor neurons leads to muscle weakness and paralysis because the brain's signals to the muscles are disrupted. The term "poliomyelitis" itself derives from "poli-" meaning gray and "myelitis" meaning inflammation of the spinal cord, which highlights the focus on the gray matter. Understanding this distinction is important because identifying the correct anatomical focus of poliomyelitis aids in understanding the disease's impact and the resulting clinical manifestations, such as paralysis.