Kalmar "dorsal vertebra" tana nufin kowane daga cikin kashin baya 12 na kashin bayan mutum. Wadannan kashin baya suna cikin tsakiyar baya kuma ana siffanta su da siffar su, wanda ya hada da tsarin kashin baya wanda ke fitowa daga baya na kashin baya. Har ila yau, a wasu lokuta ana kiran kashin baya a matsayin kashin baya ko kuma kawai kashin baya.
