3d isometric flat of cerebrospinal fluid

meninges fluid brain mater cerebrospinal membrane dura isometric vector 3d illustration flat background icon design csf system ventricle spinal education human injury ventricular pia flow skull neurology sinus anatomy bone body arachnoid meningococcal space subarachnoid venous cord choroid nerve central cerebral canal section ventricles layers sagittal granulations head barrier