What is the primary function of arachnoid granulations?

Arachnoid granulations are specialized structures in the meninges that play a crucial role in the regulation of cerebrospinal fluid (CSF) levels within the central nervous system. Their primary function is to absorb excess CSF into the dural sinuses, which are large veins that drain blood from the brain. This process is essential for maintaining proper CSF pressure and volume, ensuring that the brain is well-cushioned and protected from physical trauma.

By allowing the reabsorption of CSF into the bloodstream, arachnoid granulations help prevent conditions such as hydrocephalus, which occurs when there is an accumulation of CSF within the ventricles of the brain. Therefore, the identification of the function of arachnoid granulations as a mechanism for CSF absorption underscores their importance in maintaining homeostasis within the cranial cavity.