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Medical Term:


Pronunciation: lep'to-me'ninks


The two delicate layers of the meninges, the arachnoid mater and pia mater (vs. the tough pachymeninx or dura mater), considered together; by this concept, the arachnoid and pia are two parts of a single layer, much like the parietal and visceral layers of a membrane or bursa; although separated by the subarachnoid space they are connected via the arachnoid trabeculae and become continuous where the nerves and filum terminale exit the subarachnoid space (the cerebrospinal fluid-filled space bounded by the leptomeninges).

Synonym(s): leptomeningesTA, arachnoid mater and pia mater, meninx tenuis, pia-arachnoid, piarachnoid

See Also: arachnoid mater, pia mater

© Copyright 2017 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.