GENERAL HISTOLOGY

Detailed explanation-1: -The correct answer is B. Gray commissures connect the left and right areas of gray matter. These commissures contain axons that reach across from left to right and right to left.

Detailed explanation-2: -Gray commissure-a “cross-bar” of gray matter which connects the left and right sides of the gray matter within the spinal cord.

Detailed explanation-3: -The grey matter on both the left and right halves connect by the grey commissure, which contains the central canal. This canal communicates above into the fourth ventricle. The central canal expands at the lower end in the conus medullaris to form the terminal ventricle.

Detailed explanation-4: -In the center of the spinal cord, a butterfly-shaped area of gray matter helps relay impulses to and from spinal nerves. The “wings” are called horns. Motor (anterior) horns: These horns contain nerve cells that carry signals from the brain or spinal cord through the motor root to muscles.

Detailed explanation-5: -The brain stem is a bundle of nerve tissue at the base of the brain. It connects the cerebrum and cerebellum to the spinal cord.