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 process of bringing Planet Earth and Earth to the screen took over 5 years. With a combined budget of $47 million, $15 million of which was earmarked for the film, it represented the most expensive production in the history of documentary filmmaking.Principal photography began in 2004 and was completed in 2006.arth is a 2007 nature documentary film which depicts the diversity of wild habitats and creatures across the planet. The film begins in the Arctic in January of one year and moves south, finishing in Antarctica in the December of the same year.