lamina

The gray matter in the human nervous system, particularly in the brain and spinal cord, is neural tissue containing nerve-cell bodies, unmyelinated fibers, and interneurons. In the spinal cord, the gray matter is arranged in a butterfly shape and is further organized into nine distinct cellular layers, or laminae. These laminae, numbered with Roman numerals, receive sensory input, process signals, and contain motor neurons that innervate muscles. Laminae I to V are involved in sensory input, while Lamina IX contains motor neurons. The term "lamina" can also refer to a thin, scale-like piece of material. "Gray matter" is also used metaphorically to mean intellect or the ability to learn and understand.12345