The Collaborative International Dictionary of English v.0.48:

mucosa \mucosa\ n.
   The mucus-secreting membrane lining all body cavities or
   passages that communicate with the exterior; called also
   mucous membrane.

   Syn: mucous membrane.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

mucosa
    n 1: mucus-secreting membrane lining all body cavities or
         passages that communicate with the exterior [syn: mucous
         membrane, mucosa]