Arachnoid may refer to: * Relating to arachnids * Arachnoid (astrogeology), a geological structure found only on the planet Venus * Arachnoid (botany), referring to organs with a cobwebby exterior appearance *

Arachnoid granulation Arachnoid granulations (also arachnoid villi, and pacchionian granulations or bodies) are small protrusions of the arachnoid mater (the thin second layer covering the brain) into the outer membrane of the dura mater (the thick outer layer). They ...

, small protrusions of the arachnoid mater *

Arachnoid mater The arachnoid mater (or simply arachnoid) is one of the three meninges, the protective membranes that cover the brain and spinal cord. It is so named because of its resemblance to a spider web. The arachnoid mater is a derivative of the neural c ...

, a layer of the meninges, membranes that contain the central nervous system

See also