The ependymal cell is a type of glial cell found in the central nervous system. Its spelling is unique, with the initial "e" being pronounced as "ɛ," as in "bed." The following "p" is pronounced as "p," while the "e" in the second syllable is pronounced as "i," as in "bit." The "nd" sound is pronounced as "nd," and the "ym" is pronounced as "ɪm." Finally, the last syllable is pronounced as "əl," with the stress on the second-last syllable.
Ependymal cells are a type of glial cell that line the ventricles of the brain and the central canal of the spinal cord. They form a layer of epithelial-like cells, which together make up the ependyma, a specialized tissue found within the central nervous system (CNS). These cells are characterized by their cuboidal or columnar shape and are interconnected by tight junctions, forming a barrier between the cerebrospinal fluid (CSF) and the brain or spinal cord tissue.
The primary function of ependymal cells is to produce and regulate the cerebrospinal fluid that bathes the brain and spinal cord. They have cilia on their surfaces, which help to circulate the CSF, facilitating the movement of nutrients, waste products, and chemical signals throughout the CNS. Additionally, ependymal cells play a crucial role in maintaining the integrity of the CNS by acting as a physical barrier and participating in immune responses.
Ependymal cells also possess stem cell-like properties, known as radial glial characteristics. This means that they have the capacity to differentiate into other types of cells in the CNS, including neurons, astrocytes, and oligodendrocytes. Therefore, ependymal cells not only contribute to the structural and functional maintenance of the CNS but also participate in its repair and regeneration processes.
A cell lining the central canal of the spinal cord (those of pyramidal shape) or one of the cerebral ventricles (those of cuboidal shape).
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "ependymal" comes from the Greek word "ependyma" which means "upper garment" or "tunic". It was originally used to describe a thin membrane or layer that lines the central canal of the spinal cord and the ventricles of the brain.
The term "ependyma" itself is derived from the Greek words "epi" which means "upon" or "over" and "enduein" which means "to put on" or "to clothe". This is because the ependymal cells form a protective lining that covers and surrounds the central canal and the cerebral ventricles, providing support and nourishment to the delicate neural tissue.