Question
Biology Question on human nervous system
Which of the following statement is correct about the node of Ranvier?
A
Axolemm is discontinuous
B
Myelin sheath is discontinuous
C
Both neurilemma and myelin sheath are discontinuous
D
Covered by myelin sheath
Answer
Myelin sheath is discontinuous
Explanation
Solution
Neurons are the chief functional units of the nervous system. An ordinary neuron has a soma or cyton and a long thread, called axon which is enclosed in a multilayered myelin sheath, made by Schwann cells. The myelin sheath is interrupted at the spaces between Schwann cells to form gaps. These gaps are called nodes of Ranvier. These nodes and the myelin sheath created condition that speed up the nerve impulses.