Question

Fill in the blanks:
White matter mainly consists of ___.

Answer 1

Substances of the central nervous system (CNS)

1. The brain and the spinal cord constitute the CNS. They are made of neurons, the functional unit of the nervous system. Neurons help in the transmission of messages in the form of electrical impulses.
2. Based on the appearance, the organs of the CNS are said to be made of two substances- grey matter and white matter.
3. The grey matter appears grey in color as they comprise neuronal cell bodies (soma). The white matter appears white in color as they comprise nerve fibers (axons and dendrites). The myelin sheath of axons consists of high lipid content and appears white in color.

Final answer

White matter mainly consists of nerve fibers.