leptomeninx


lep·to·me·ninx

(lep'tō-mē'ninks), [TA] 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).
See also: arachnoid mater, pia mater. Synonym(s): leptomeninges [TA], arachnoid mater and pia mater ☆ , meninx tenuis, pia-arachnoid, piarachnoid

leptomeninges

(lep?to-men-in'jes) leptomeninx [? + meninx, membrane] The pia mater and arachnoid as distinct from the dura mater. Synonym: pia-arachnoidleptomeningeal, adjective