Definition of pia mater in English:

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pia mater

Pronunciation: /ˌpēə ˈmädər/
Pronunciation: /ˌpīə ˈmādər/


The delicate innermost membrane enveloping the brain and spinal cord. See also meninges.
Example sentences
  • These veins are found in the maternal part of the placenta, the spinal cord pia mater, retina, sinuses of the dura mater, most cerebral veins, trabecular veins of the spleen, and veins of the nail bed.
  • The innermost layer is the pia mater, a delicate vascular layer adherent to the surface of the brain and spinal cord.
  • Arachnoid and pia are also called leptomeninges (thin membranes).


Late 19th century: from medieval Latin, in full literally 'tender mother', translating Arabic al-'umm ar-raḳīḳa.

For editors and proofreaders

Syllabification: pi·a ma·ter

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