Myelinated vs Unmyelinated Neurons
Difference Between Myelinated and Unmyelinated Neurons: Neurons are the electrically excitable cells in our body that communicate with other cells via specialized connections called synapses. Each neuron has a cell body with many minute branched short protoplasmic extensions called Dendrites and an elongated unbranched protoplasmic extension called the Axon. In the previous post we discussed the Similarities and Differences between Axon and Dendrites. The axon of the neurons may be myelinated (with myelin sheath) or unmyelinated (without myelin sheath).
The main difference between these two types of neurons is the speed of conduction of impulse. A neuron with myelinated axons can conduct the impulse at a faster speed since the myelin sheath acts as the insulator that helps to propagate the electrical signal faster. Majority of the neurons in the central and peripheral nervous system are myelinated since they require fast conduction speeds. A neuron with unmyelinated axon has a comparatively lower speed of conduction of the nerve signals.
The present post discusses the Similarities and Differences between Myelinated Neurons and Unmyelinated Neurons with a Comparison Table.
Difference Between Myelinated and Unmyelinated Neurons
Sl. No. Myelinated Neurons Unmyelinated Neurons
1 Myelinated nerve fibres contain the myelin sheath. Unmyelinated nerve fibres do not have the myelin sheath
2 The Schwann cells wrap tightly around the nerve axon and form the myelin sheath. Schwann cells are not wound around the axons but simply form a groove.
3 The axis cylinder of the myelinated nerve fibres has two sheaths. The axis cylinder of unmyelinated nerve fibres has only one sheath.
4 The speed of transfer of nerve impulses through myelinated nerve fibres is much faster when compared to unmyelinated fibres The speed of transfer of nerve impulse through unmyelinated nerve fibres is much slower.
5 Myelinated nerve fibres appear as white in the fresh state. Unmyelinated nerve fibres appear as grey in the fresh state.
6 Myelinated fibres show nodes and internodes. Unmyelinated nerve fibres do not show notes and internodes.
7 Myelinated fibres possess notes of Ranvier. Unmyelinated nerve fibres do not possess the Notes of Ranvier.
8 Myelinated nerve fibres occur in the white matter of the brain, spinal cord and in the central and cranial nervous system. Unmyelinated nerve fibres occur in the autonomic nervous system.
9 Myelinated nerve fibres may give off collateral nerve fibres. Collateral fibres are not produced in unmyelinated nerves.
A comparison of the speed of conduction of nerve impulse through an unmyelinated and myelinated Neuron (Image Source: CC Wikipedia)
Similarities between Myelinated and Unmyelinated Nerve Cells
Ø Both myelinated and unmyelinated cells are nerve cells.
Ø Both can conduct impulses as electric signals.
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@. Sympathetic vs Parasympathetic Nervous System (Comparison Table)
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More Lecture Notes from Easy Biology Class…
For most of the topics only Differences and Similarities are given. No thorough information on topics is given. The differences and similarities are not sufficient for clearing CSIR JRF/NET.
Thank you Amit KUmar for your comment.
The Difference between sections is not for CSIR JRF NET examination. It is for degree or higher secondary students.
For cracking the CSIR examination you need thorough understanding about the concept. for that you have to read very well on text books.
You can also use the mock tests and model question papers provided
Happy Learning
Regards