Cerebrospinal fluid channels of the pia mater.
D000818:Animals; D001099:Arachnoid / Q000033:anatomy & histology; D001158:Arteries; D002415:Cats; D004285:Dogs; D006801:Humans; D010841:Pia Mater / Q000033:anatomy & histology* / Q000098:blood supply; D014680:Veins