Meninges final explanation

January 18 / 2018

Stage: c) taking action

Approaches to learning: Transference skills

During the process of writing this entry I was able to learn a lot of new things, such as exactly comprehending what meningitis is, because honestly, I knew something about it, but I did not know exactly why and how it happens.

MENINGES: The meninges are the three layers that cover the brain and the spinal cord, their names are the dura mater, the arachnoid mater and the pia mater, each one has a different function, however they all share the involvement in working with the cerebrospinal fluid to protect the central nervous system (CNS) from mechanical damage and providing a framework that supports the cerebral and cranial vasculature.

The dura mater is the outermost layer of the meninges, meaning that it is located right after the skull, it is a thick and inextensible material made up of two connective tissue sheets; the endosteal layer, involved in the lining of the inner surface of the cranium and the meningeal layer that lines the endosteal layer inside the cranial cavity.

Between the previously mentioned layers, there are somethings called the dural venous sinuses, and they are all responsible for the venous vasculature of the cranium, in other words, the blood flow around the cranium.

The arachnoid mater is the middle layer of the meninges, it is just a tissue that connects the dura mater to the pia mater, and it does not receive any blood flow.

Underneath the arachnoid matter there is a space known as the sub-arachnoid space, inside this space there is cerebrospinal fluid, and it’s job is to cushion the brain.

And finally, the pia mater is located under the arachnoid mater, meaning it is adhered to the surfaces of the spinal cord and the brain, it is very thin and it receives a lot of blood flow.

The meninges are a very common site of infection, and when you think about infections in the meninges you will probably think about meningitis, but what is meningitis? It's term refers to the inflammation of the meninges, often caused by pathogens. 

The response to the infection performed by the immune system causes something known as a cerebral oedema, it raises intra cranial pressure and causes repercussions such as cranial herniation (when a part of the brain is forced out of the cranial cavity), if something like this occurs to a person, then he or she will most likely end up dead.