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.
A feature film version of Planet Earth was commissioned alongside the television series, repeating the successful model established with The Blue Planet and its companion film, Deep Blue. Earth was released around the world from 2007 to 2009.he series comprises eleven episodes, each of which features a global overview of a different biome or habitat on Earth. At the end of each fifty-minute episode, a ten-minute featurette takes a behind-the-scenes look at the challenges of filming the series.