Ependyma

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ependyma

[e′pen·də·mə]
(histology)
The layer of epithelial cells lining the cavities of the brain and spinal cord. Also known as ependymal layer.

Ependyma

 

cells in the brain of animals and man that perform demarcating, supportive, and secretory functions in the central nervous system; a form of neuroglia.

The ependyma separates from cells of the neural tube in early embryogenesis. Ependymal cells (ependymocytes) line the walls of the spinal canal and ventricles of the brain. They have elongated bodies with cilia at the free end. The cilia, which are lost in many parts of the brain after the individual is born, help the cerebrospinal fluid to circulate by their beating movements. A long, branched process extends from the opposite end of the ependymocyte into the brain. The ependyma of the walls of the third ventricle may promote the exchange of biologically active substances between neurons of the adjacent regions of the brain, cerebrospinal fluid, and blood vessels of the hypophyseoportal system.