<anatomy> The layer of tissue situated or occurring between the arachnoid and the pia mater. ... (11 Nov 1997) ... Found on http://www.encyclo.co.uk/local/20973
Subarachnoid: Literally, beneath the arachnoid, the middle of three membranes that cover the central nervous system. In practice, subarachnoid usually refers to the space between the arachnoid and the pia mater, the innermost membrane surrounding the central nervous system. The subarachnoid space is a potential space. It normally contains cerebrosp... Found on http://www.medterms.com/script/main/art.asp?articlekey=13757