Organ
Pia mater
The meningeal layer closely following neural surfaces
High-yield
Unlike the arachnoid covering, pia follows the cerebral sulci. Its spinal extensions help tether and support the cord rather than enclosing a separate fluid cavity.
Overview
Pia follows the folds of the brain and the surface of the spinal cord, beneath the CSF-filled subarachnoid compartment. It is closely associated with surface vessels and accompanies penetrating vessels for part of their course. Spinal specializations include the denticulate ligaments and the pial part of the filum terminale.
Reference facts
- Location
- Directly at the surface of the brain and spinal cord, forming the inner side of the subarachnoid compartment.
- Parts
- Cranial and spinal portions; spinal pia contributes to denticulate ligaments and the filum terminale internum.
- Blood supply
- Closely associated with surface and penetrating vessels. Vascular pial tissue contributes to the tela choroidea and connective-tissue component of the choroid plexus.
- Innervation
- Pial and perivascular regions have nerve fibers; pain has been reported during manipulation of some pial vessels in awake surgery, so they should not be labeled uniformly insensitive.
- Function
- Supports surface vessels and separates the subarachnoid compartment from underlying neural tissue, together with the adjacent glial surface.
Clinical correlation
The pia and arachnoid are collectively called the leptomeninges. Infection or malignant cells involving these coverings and the communicating CSF can affect multiple brain, cranial-nerve or spinal-root levels; spread is possible, not inevitably uniform.
Frequently asked questions
Where is the pia mater located?
The pia mater lies directly at the surface of the brain and spinal cord, forming the inner side of the subarachnoid compartment.
What does the pia mater do?
Supports surface vessels and separates the subarachnoid compartment from underlying neural tissue, together with the adjacent glial surface.
What are the parts of the pia mater?
Cranial and spinal portions; spinal pia contributes to denticulate ligaments and the filum terminale internum.
What is the blood supply of the pia mater?
Closely associated with surface and penetrating vessels. Vascular pial tissue contributes to the tela choroidea and connective-tissue component of the choroid plexus.