The flat part or sheet of bone on the back part of the spine, covering the spinal nerves and their sac (the dura) is called the lamina. Since the medical suffix "ectomy" refers to the removal of the part in question, the word laminectomy refers to removal of the back part of the spinal bone, often also including the spinous process (the part that extends backward) to decompress the nerves within the spinal canal.
