Question

Differentiate between Myelinated and Unmyelinated nerve fibres.

Answer 1

Hint: Neurons are referred to as the specialised cells that, through fragile and thin cellular extensions that are termed as the axons, receive and send signals to other cells.

Complete answer:
Neurons are electrically excitable cells in our body that get connected through specific links termed as synapses with other cells. Each neuron possesses a cell body that are termed as the dendrites with several minute branched short protoplasmic extensions and long elongated unbranched protoplasmic extensions called axons. The axons may be categorised into myelinated (with sheath) and unmyelinated (without sheath).

Now let us see difference between them:

Myelinated nerve fibre	Non myelinated nerve fibre
They possess myelin sheath.	These do not possess myelin sheath.
The Schwann cells shows wrapping around the nerve axon.	The Schwann cells do not show wrapping but are only present in the groove.
This shows two sheaths in the axis of the cylinder.	This shows only one sheath in the axis of the cylinder.
These transfer nerves impulses very fast.	These transfer nerve impulses very slow.
These appear white in their fresh form.	These appear grey in their fresh form.
They possess nodes and internodes.	These do not possess nodes and internodes.
Nodes of Ranvier are known to present in these neurons.	Nodes of Ranvier are not known to occur in these.
Collateral fibres are produced.	Collateral fibres are not produced.

Note: The Myelinated fibre are present in the white part of the brain and also in the spinal cord, while the non myelinated nerve fibre is present in the autonomic nervous system. The Myelinated fibre have axons of large diameter, while the known unmyelinated fibre have access of small diameter.