Meninges

About the Meninges

The meninges are three membranes surrounding the brain and spinal cord. Dura mater tough mother is the thick outermost layer, adherent to the skull. It forms partitions: falx cerebri between hemispheres, tentorium cerebelli between cerebrum and cerebellum, and falx cerebelli between cerebellar hemispheres. Epidural space between skull and dura contains arteries, particularly the middle meningeal artery. Arachnoid mater is the web like middle layer. The subdural space between dura and arachnoid contains bridging veins, which can tear in falls, especially in older adults, causing a subdural hematoma. Pia mater tender mother adheres directly to brain and spinal cord tissue, following every gyrus. The subarachnoid space between arachnoid and pia contains cerebrospinal fluid CSF produced by choroid plexus at 500 mL daily, circulating and absorbing at arachnoid granulations. Meningitis infection of meninges is a medical emergency. Subarachnoid hemorrhage, most often from a ruptured aneurysm, classically causes a sudden thunderclap headache.