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.
HBO's Westworld. See it now, in Utah. Moenkopi and Cutler sandstone rise out of the desert like Gothic castles. Towers drip with grotesque features carved from rock more than 200 million years old. The sculptor here: the force of Mother Nature, whose patient hand harnessed wind, water, ice and time in the creation of Castle Valley, Utah.