Question

Nodes of Ranvier are found in
A) Non-myelinated nerve fibres
B) Myelinated nerve fibres
C) Both (A) and (B)
D) None of the above

Answer 1

Hint: Nodes of Raniver are present in a long thread-like part of nerve cells. If you can imagine the information about all parts of the neuron, you will reach the answer easily.

Complete step by step answer:
Nodes of Ranvier are found in myelinated nerve fibres. Nerve cells are called neurons and they are made up of a cyton or cell body that consists of a Nucleus, Mitochondria, Golgi body, and Endoplasmic Reticulum.
The axon is an extension of the dendrites and it consists of axolemma, myelin sheath, and neurilemma. The gap between the myelin sheath of a nerve is called the node of Ranvier.
The small branching of the cyton is the dendrites.

Additional information:
Whenever a sensory receptor receives information from the environment, the end of the dendrite tip sets off a chemical reaction to create an electrical impulse. This impulse travels from the dendrite to the cyton and then through the axon reaches the axon endings.
At the end of the axon the electrical impulse releases some chemicals, these chemicals cross a gap or synapse by creating a potential difference through the accumulation of ions.
As the message gets transferred from one neuron to another, it finally reaches the muscle cells or glands (effector organ) based on which the impulses will be converted into action.
The mitochondria in the muscle cells are comparatively larger in number to produce energy for muscular action. It is a fast mechanism facilitated by neurotransmitters.

So, the correct answer is “myelinated nerve fibres”.

Note:
The myelin sheath was discovered and named by a German Pathological Anatomist Rudolf Virchow in 1854.
The node of Ranvier was named and discovered by a French pathologist and anatomist Louis Antoine Ranvier.