arachnoid membrane
- A delicate fibrous membrane forming the middle of the three coverings of the brain and spinal cord, closely attached to the dura mater, from which it is separated only by the subdural cleft, but separated from the pia mater by the subarachnoid space.
Show More
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.