Which may be divided into four parts the medulla oblongata

Which may be divided into four parts the medulla oblongata

Which may be divided into four parts the medulla oblongata

The brain is that portion of the cerebrospinal axis within the cranium, which may be divided into four parts the medulla oblongata, the cerebellum, the pons Varolii, and the cerebrum and it is covered by three membranes, called the meninges. The outer of these membranes, the dura mater, is a thick, white, fibrous membrane which lines the cavity of the cranium, forming the internal periosteum of the bones; it is continuous with the spinal cord to the extremity of the canal. The second, the arachnoid, is a delicate serous membrane, and loosely envelops the brain and spinal cord; it forms two layers, having between them the arachnoid space which contains the cerebrospinal fluid, the use of which is to protect the spinal cord and brain from pressure. The third, or inner, the pia mater, is closely adherent to the entire surface of the brain, but is much thinner and more vascular than when it reaches the spinal cord, which it also envelops, and is continued to form the sheaths of the spinal nerves.