(Latin: thorn, prickle; by extension, "backbone", the spinal cord)

(Greek > Latin: membrane lining the central canal of the spinal cord and the ventricles of the brain including cells and cellular membranes)

(Greek: bone marrow; the spinal cord and medulla oblongata; the myelin sheath of nerve fibers)

(Greek: gray; pertaining to the "gray matter" of the nervous system, brain, and the spinal cord)