Any of the bones or segments composing the spinal column, consisting typically of a cylindrical body and an arch with various processes, and forming a foramen, or opening, through which the spinal cord passes. Origin of vertebra. … You see, the spine is a row of vertebrae that was designed to be horizontal.
Medical Definition of extramedullary
situated or occurring outside the spinal cord or the medulla oblongata
located or taking place outside the bone marrow extramedullary hematopoiesis
Medical Definition of intramedullary. : situated or occurring within a medulla an intramedullary tumor of the spinal cord; especially : involving use of the marrow space of a bone for support intramedullary pinning of a fracture of the thigh.