Question

Ependymal cells are the cells :

• A. \( \text{that secrete cerebrospinal fluid} \)
• B. \( \text{that secrete and maintain myelin in the peripheral nervous system} \)
• C. \( \text{whose foot processes form the blood brain barrier} \)
• D. \( \text{that remove bacteria and damaged tissue in the central nervous system} \)

Hint:

\textbf{Neuroscience: Glial Cells.} Remember the different types of glial cells in the nervous system and their specific functions: astrocytes (support and blood-brain barrier), oligodendrocytes (myelination in CNS), Schwann cells (myelination in PNS), microglia (immune surveillance), and ependymal cells (CSF production and movement).

Answer 1

The Correct Option is A

Ependymal cells are a type of glial cell found lining the ventricles of the brain and the central canal of the spinal cord. These cells are specialized epithelial cells that have cilia and microvilli on their apical surface. One of their primary functions is to secrete cerebrospinal fluid (CSF). They also contribute to the movement of CSF through the ventricular system via the beating of their cilia. Let's look at why the other options are incorrect: (2) that secrete and maintain myelin in the peripheral nervous system: Schwann cells are responsible for secreting and maintaining myelin in the peripheral nervous system. In the central nervous system, oligodendrocytes perform this function. (3) whose foot processes form the blood brain barrier: Astrocytes, another type of glial cell in the central nervous system, have foot processes that surround capillaries and contribute to the formation and maintenance of the blood-brain barrier. (4) that remove bacteria and damaged tissue in the central nervous system: Microglia are the resident immune cells of the central nervous system and are responsible for phagocytosis of pathogens, cellular debris, and damaged tissue. Therefore, the correct description of ependymal cells is that they secrete cerebrospinal fluid.