The Arachnoid mater is one of the three layers of the meninges, interposed between the dura mater and the pia mater and separated from the pia mater by the subarachnoid space.

The pia and arachnoid membranes are called leptomeninges (Orlando Regional Healthcare, 2004).

The delicate, spiderweb-like arachnoid layer, attached to the inside of the dura, surrounds the brain and spinal cord but does not line the brain down into its sulci (folds). Cerebrospinal fluid flows under this membrane in the subarachnoid space, which is full of the delicate fibres of the arachnoid extending down to attach to the pia mater.

The portions covering the brain and spinal cord are called arachnoidea encephali and arachnoidea spinalis, respectively.

Reference

• Orlando Regional Healthcare, Education and Development. 2004. "Overview of Adult Traumatic Brain Injuries."

External links

• Slide

Central nervous system

Arachnoïde | クモ膜 | Spinnenwebvlies | Spindelvevshinne | Aracnóide