Pia mater often referred to simply as pia, is a delicate inner layer of tires, membranes that surround the brain and spinal cord. Pia mater is a medieval Latin meaning “delicate mother.”  The other two membrane membranes are the hard tire and the arachnoid. Both pia and spider veins are derivatives of the neural crest, while dura comes from embryonic mesoderm.


The foam is a thin fibrous tissue permeable to water and small solutes. Sand allows the blood vessels to pass and nourish the brain. It suggests that the perivascular space between the blood vessels and the pia is part of the brain’s psuedolymphatic system (lymphatic system). In the case of irritation and distension of the pleura, meningitis is formed.

Pia mater function

In combination with other meningitis membranes, cerebrospinal fluid (CSF) and skull wall formation are necessary.  CSF, pia mater and other tire layers. Production and circulation of Cerebrospinal fluid circulate in the chambers, cisterns and subarachnoid spaces in the brain and spinal cord. About 150 ml of cerebrospinal fluid is always in circulation because constantly recycled through the daily production of almost 500 ml of liquid.


CSF is mainly secreted by the choroid plexus; however, about one-third of CSF is secreted by the pianos and other ventricular lining areas (the thin epithelial lining of the brain and the central channel) and the spider-like membranes.


CSF travels from the ventricles and cerebellum through three foraminous in the brain, draining to the brain and ending its cycle in venous blood through structures such as arachnoid granulation. The sand covers every surface aperture of the brain other than the aperture to allow circulation of the CSF.

Perivascular spaces

Pia material allows the creation of perivascular spaces that serve as the lymphatic system of the brain because The blood vessels that penetrate the brain first pass through the surface and then go to the brain. This direction of flow leads to the fact that the layer of the matter of the pianos transfer inwardly and loosely adheres to the vessels, leading to the creation of space, namely the perivascular space, between the bulb and each blood vessel.


This is very important because the brain lacks a real lymphatic system. In the rest of the body small amounts of protein are able to leak from the capillaries of the parenchyma through the lymphatic system. In the brain ends in the interstitial space.


Protein portions are able to leave the highly permeable foam material and enter the subarachnoid space to flow in the cerebrospinal fluid (CSF), ultimately ending in the cerebral veins.


Pia mater function uses to create these perivascular spaces to allow the passage of certain materials, such as liquids, proteins, and even foreign solid particles, such as dead white blood cells from the bloodstream into the cerebrospinal fluid and basically the brain.




Due to the high permeability of foam and ependyma, water and small molecules in the cerebrospinal fluid are able to enter the interstitial fluid of the brain, so interstitial brain fluid and cerebrospinal fluid is very similar in composition.


However, the regulation of this permeability achieves due to a large number of astrocyte rate processes that are responsible for combining the capillaries and the material hub in a way that helps to limit the amount of diffusion that passes to the CNS.


The pia mater function simply visualizes through these ordinary events. This last property is visible in the case of head injuries. When the head comes into contact with another object, the brain protects from the skull due to the similarity of density between the two fluids, so that the brain not only breaks down in the skull but rather its movement slow down and stopped by the viscous ability of this fluid.


The contrast of permeability between the sender and the blood-brain barrier means that many drugs that enter the bloodstream can not enter the brain.