pia mater

pia mater /pia ma·ter/ (pi´ah ma´ter) [L.] the innermost of the three meninges covering the brain and spinal cord.

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pia ma·ter (p mtr, p mätr)

n.

The fine vascular membrane that closely envelops the brain and spinal cord under the arachnoid and the dura mater.

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pia mater (pia)

[pē′ə mā′tər, pī′ə]

Etymology: L, pia, tender, mater, mother

the innermost of the three meninges covering the brain and the spinal cord. It is closely applied to both structures and carries a rich supply of blood vessels, which nourish the nervous tissue. The cranial pia mater covers the surface of the brain and dips into the fissures and sulci of the cerebral hemispheres. The spinal pia mater is thicker, firmer, and less vascular than the cranial pia mater and consists of two layers. The outer layer is composed of longitudinal collagenous fibers. The inner layer wraps the entire spinal cord and, at the end of the cord, is prolonged into the filum terminale. The pia mater also forms the denticulate ligament, which extends the entire length of the spinal cord on both sides. Compare arachnoid, dura mater. See also meninges.

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pia mater

[L.] the innermost of the three meninges covering the brain and spinal cord.

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pia mater 

A delicate fibrous membrane closely enveloping the brain, spinal cord and the optic nerve. It terminates at the eye.