ependymal cells
Summary
Ependymal cells are ciliated glial cells that line the brain's ventricles and the spinal cord's central canal. Those in the choroid plexus help make cerebrospinal fluid (CSF), and cilia help circulate it. Testable point: they handle CSF, not myelin or the blood–brain barrier.
Detail
Meaning: Ependymal cells are glial cells of the central nervous system that form a ciliated, epithelium-like lining of the brain's ventricles and the spinal cord's central canal. Those in the choroid plexus, together with underlying capillaries, help form cerebrospinal fluid (CSF) from blood plasma, and beating cilia help move CSF through the ventricles. Tight junctions between choroid plexus cells create a blood–CSF barrier.
On the MCAT: The usual task is matching each glial cell to its job. Ependymal cells: CSF production and circulation. Astrocytes: structural and metabolic support, K⁺ and neurotransmitter uptake, blood–brain barrier. Microglia: phagocytosis of debris and pathogens. Oligodendrocytes: myelin in the CNS. Schwann cells: myelin in the PNS. A passage may describe cells lining the ventricles or a change in CSF production or flow and ask which cell type is involved.
Common confusion: Students often credit ependymal cells with the blood–brain barrier. That barrier depends mainly on tight junctions between capillary endothelial cells, supported by astrocyte end-feet. Ependymal cells of the choroid plexus form the separate blood–CSF barrier. Also remember that ependymal cells are glia, not neurons, and they do not make myelin.
Sources
- Campbell Biology
- Principles of Neural Science
- Human Physiology: An Integrated Approach
Written for the MCAT and checked before it was published. For study reference only. Spotted an error? Let us know.