Structures surrounding the brain

The brain is contained within the skull. The skull offers an inflexible defense for the brain which can help reduce damage from impacts or potential injury. Following the skull are the meninges layers, Dura, Arachnoid, Pia. In the space between the Arachnoid and Pia mater, the subarachnoid space, Cerebrospinal Fluid (CSF) is located. CSF helps cushion the brain within the skull and can act as a shock absorber. CSF also circulates nutrients and chemicals filtered from the blood and removes waste products from the brain.

Within the brain, Cerebral Perfusion Pressure (CPP) needs to be maintained in order to keep a continuous flow of blood to the brain. CCP is balanced by 2 opposing forces, Mean Arterial Pressure (MAP) which forces blood flow into the brain and Intracranial Pressure (ICP) that forces blood out of the brain. Through maintaining this balance and keeping MAP greater than ICP, CPP is maintained and blood flow continues to supply the brain.