How is the gray matter subdivided in a given transverse section of the spinal cord?
The gray matter can be subdivided into groups of nuclei.
When the spinal cord is cut along its length, these nuclei appear to be arranged in cell columns or laminae.
Rexed divides the cord into 10 laminae. Each lamina extends the length of the cord, with lamina I at the most dorsal aspect of the dorsal horn, lamina IX at the most ventral aspect of the ventral horn, and lamina X surrounding the central canal.
Lamina II is also called the substantia gelatinosa and is the area of synapse for the spinothalamic tract.
Lamina IX is the site of the cell bodies for the anterior horn motor cells.
