NEETZoologyNeural Control and Coordination
Read the following statements regarding nerve fibres and their coverings. Which of the following statements is incorrect?
Options
- AMyelinated nerve fibres are found in spinal and cranial nerves.
- BUnmyelinated nerve fibres are commonly found in autonomous and somatic neural systems.
- CUnmyelinated nerve fibres are not enclosed by Schwann cells.
- DThe gaps between two adjacent myelin sheaths are called nodes of Ranvier.
Correct answer
C. Unmyelinated nerve fibres are not enclosed by Schwann cells.
Step-by-step solution
According to NCERT, unmyelinated nerve fibres are enclosed by a Schwann cell that does not form a myelin sheath around the axon. Therefore, the statement claiming they are not enclosed by Schwann cells is incorrect. Myelinated nerve fibres are enveloped with Schwann cells that form a myelin sheath, leaving gaps called nodes of Ranvier. These myelinated fibres are found in spinal and cranial nerves, whereas unmyelinated fibres are commonly found in autonomous and somatic neural systems. Answer: Unmyelinated nerve fi