Definition of Dural sac

Dural sac: The membranous sac that encases the spinal cord within the bony structure of the vertebral column. Dural refers to the dura, the name of the membrane around the spinal cord (and brain, too).

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=40199
Last Editorial Review: 6/14/2012