ARACHNOID MATER

The 'arachnoid mater' is one of the three meninges, the membranes that cover the brain and spinal cord. It is interposed between the two other meninges, the more superficial dura mater and the deeper pia mater, and is separated from the pia mater by the subarachnoid space.
The delicate, spiderweb-like (therefore the name) 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.
The arachnoid and pia mater are sometimes considered as a single structure, the ''leptomeninx'', or the plural version, ''leptomeninges''. (Lepto- from the root meaning ''thin'' in Greek). Similarly, the dura in this situation is called the ''pachymeninx''.

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Etymology

Additional images

Reference

External links

See also

Etymology

''Arachnoid'' is from a Greek root, and means ''cob web like''. The ''mater'' designation (meaning ''mother'' in Latin) is borrowed from the ''dura mater'' and ''pia mater'', which were Latin translations of Arabic terms. While ''mater'' does not technically belong with the arachnoid layer, it has nevertheless been adopted by it for uniformity with the other meninges, and ''arachnoid mater'' is currently the Terminologia Anatomica international standard.

Additional images

Reference

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

External links

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★ Slide

See also

★ Arachnoid cyst