CSF, Ventricles & Brain Anatomy
Meninges
The meninges are the three protective membranes — dura, arachnoid, and pia mater — that surround the brain and spinal cord.
In short: Meninges
- They consist of three layers surrounding the brain and spinal cord.
- CSF circulates between two of them (in the subarachnoid space).
- Inflammation of the meninges (meningitis) can cause hydrocephalus.
- They are relevant to CSF flow and absorption.
What it is
The meninges are the three layered membranes that surround and protect the brain and spinal cord: the tough outer dura mater, the web-like middle arachnoid mater, and the delicate inner pia mater. They enclose the CSF spaces.
Understanding Meninges
CSF circulates in the subarachnoid space, which lies between the arachnoid and pia mater, and is absorbed through structures (arachnoid granulations) associated with these membranes. Inflammation of the meninges — meningitis, usually from infection — can scar or clog the CSF pathways and absorption sites, causing hydrocephalus, often the communicating type. The meninges are therefore relevant both to normal CSF circulation and to one of the common causes of acquired hydrocephalus.
Why it matters
Understanding the meninges helps families see how CSF circulates within these membranes and why meningitis can lead to hydrocephalus by disrupting CSF flow and absorption.
Common questions
How many meninges are there?
Three — dura, arachnoid, and pia mater.
Where does CSF circulate?
In the subarachnoid space, between the arachnoid and pia.
How can the meninges relate to hydrocephalus?
Meningitis can scar the CSF pathways, causing hydrocephalus.
Bottom line
The meninges are the brain's three protective membranes; inflammation (meningitis) can disrupt CSF flow and cause hydrocephalus.
Browse all 265 Hydrocephalus definitions
Read the Hydrocephalus patient guides
Not sure which page you need? Put words to it with the symptom navigator