Imagine that you are a neurosurgeon, about to remove a tumor lodged deep inside the brain. The top of the skull has been removed. What now lies between you and the brain? Which layer(s) must be cut before you reach the CSF?

Sourav PanSeptember 24, 2024

Answered

As a neurosurgeon preparing to remove a tumor deep inside the brain, after removing the top of the skull, you would encounter several protective layers before reaching the brain and the cerebrospinal fluid (CSF). The layers you would need to cut through are as follows:

1. Dura Mater: This is the outermost layer of the meninges, a tough and durable membrane that encases the brain and spinal cord. It must be cut to access the underlying layers.
2. Arachnoid Membrane: Beneath the dura mater lies the arachnoid membrane, which has a web-like appearance. Cutting through this layer is necessary to reach the subarachnoid space.
3. Subarachnoid Space: This space is filled with CSF, which cushions the brain. Once the arachnoid membrane is cut, you will enter the subarachnoid space where the CSF is located.
4. Pia Mater: Finally, the pia mater, which closely adheres to the surface of the brain, may also need to be cut or carefully maneuvered to access the brain tissue directly.