Aivolisäkerrosta

Aivolisäkerrosta, also known as the meninges, is a protective layer of tissue that surrounds the brain and spinal cord. It consists of three layers: the dura mater, the arachnoid mater, and the pia mater. The meninges provide physical protection, support, and nourishment to the central nervous system. The dura mater is the outermost layer, providing a tough, fibrous covering that anchors the brain to the skull. The arachnoid mater is the middle layer, which is delicate and web-like in appearance. It is separated from the dura mater by the subdural space and from the pia mater by the subarachnoid space, which contains cerebrospinal fluid (CSF). The pia mater is the innermost layer, adhering closely to the surface of the brain and spinal cord, providing a smooth surface for the CSF to circulate. The meninges also play a role in the immune response, as they contain immune cells that can respond to infections or injuries. In cases of inflammation or infection, the meninges can thicken and become swollen, a condition known as meningitis. The study of the meninges is crucial in understanding the structure and function of the central nervous system, as well as in diagnosing and treating neurological disorders.