In the central nervous system, there are three different layers that cover the spinal cord and brain. These are called the meninges, and their three levels consist of the: pia, arachnoid, and dura mater. Bone is situated above these layers, followed by periosteum (a fibrous membrane that covers bone) and skin.The dura mater is the top layer of the meninges, lying beneath the bone tissue.This material at times opens into sinus cavities (spaces) located around the skull.he dura mater is the top layer of the meninges, lying beneath the bone tissue. This material at times opens into sinus cavities (spaces) located around the skull.
Planet Earth Making Mountains Planet Earth filmmakers came out in the rugged mountains of Nepal in hopes of filming the elusive snow leopard for the Mountains episode. 01:51.
The Mars Express orbiter took this farewell shot of home as it left for the Red Planet. Filed under pics of Earth by planetary missions, pretty pictures, Mars Express, Earth, the Moon. Earthrise from Lunar Orbiter 1. On August 23, 1966, Lunar Orbiter 1 took the first photo of Earth as seen from lunar orbit.