Question

The central canal of the spinal cord is lined by
A. Epithelial tissue
B. Keratinized epithelium
C. Ependymal cells
D. Goblet (mucous) cells.

Answer 1

Hint: The central canal of the spinal cord is also known as the ependymal canal or spinal foramen that extends from the conus medullaris in the lumbar spine to the caudal angle of the fourth ventricle.

Step by step answer: The central canal is a part of the system of cerebrospinal fluid cavities and it includes the cerebral ventricle, aqueduct of Sylvius, and the fourth ventricle. In the brain and the central canal of the spinal cord forms the ventricular system that is lined by ependymal cells. It is a thin epithelium and is majorly involved in the secretion of cerebrospinal fluid. In the central nervous system, it is one of the four types of neuroglia. The ependymal cells also give rise to the epithelial layer that surrounds the choroid plexus; a network of blood vessels present in the walls of the lateral ventricles. These cells are derived from the embryonic tissue called the neuroectoderm. The layer of ependymal-derived cells that surround the blood vessels of the choroid plexus functions mainly to produce the cerebrospinal fluid. The ependymal cells in the ventricles are loosely joined together by special intercellular adhesion sites called desmosomes.
Hence, the correct answer is option C.

Note: The ventricles of the brain and the central canal of the brain are lined by the ependymal cells. Ependymal cells are ciliated and form a single cuboidal or columnar epithelium. They don’t have tight junctions that allow the free exchange of nervous tissue and cerebrospinal fluid.