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 Real Story Behind 'Mountain Men'. Tom Oar lives in a handmade cabin in Montana's Yaak Valley. The first obstacle to becoming a TV mountain man is the criminal background check. That's thrown a few out right there, says Chris Richardson, sipping a beer. Richardson, the 46-year-old co-creator of the hit show Mountain Men â a reality series about guys surviving off the land â is sitting in a bar in Yaak, Montana, in February, explaining how he tracks down a real-life Grizzly Adams for the series.