NEET PG DENTAL EXAM

Detailed explanation-1: -Both white matter and gray matter comprise the spinal cord. The gray matter is a collection of cell bodies, and the white matter is a collection of axons. The amount of gray matter is scarce at the thoracic levels as opposed to the cervical and lumbosacral segments.

Detailed explanation-2: -In the brain proper, grey matter forms the outer layer of the brain, and white matter forms the inner layer. In the spine, this is reversed: white matter forms the outer layer of the spine, and grey matter the inner layer.

Detailed explanation-3: -In lower segments of the spinal cord, there is less white matter because there are fewer axons traveling to and from the brain. There are also differences in the gray matter. In the cervical segment, the ventral horn (the lower half of the segment) is enlarged.

Detailed explanation-4: -Both white and gray matter are found in the brain and spinal cord. In the spinal cord, white matter sits external to the gray matter, while it lies deeper to the gray matter of the cerebral cortex, the outer layer of the brain.