0:00
Hi friends, in this video let us understand the difference between neurons and glial cells
0:05
Neurons are the basic functional unit of nervous system responsible for transmitting
0:10
electrical impulses throughout the body. So this is the neuron and this is the individual neuron
0:16
that is made up of cell body, dendrites and axon. Whereas glial cells are non-neuronal cells
0:24
that supports neuron like microglial cells, astrocytes, ependymal cells, oligotendrocytes. All non-neuronal cells are called glial cells. There is no action potential but there is resting
0:38
potential and there is no chemical synapse in the case of glial cell. Second difference is
0:44
regarding the function. Neurons are responsible for transmission of electrical impulse or nerve
0:49
impulses between central nervous system and different parts of the body. So this
0:53
is a neuron from the cell body electrical impulses reaches this axon terminal of
1:00
the presynaptic neuron and this axon terminal once the electrical impulses reaches here there will be a voltage difference as a result voltage gated
1:10
channels that is located at the terminal region opens then calcium enters into
1:16
this axon terminal this axon terminal has vesicles with neurotransmitters upon calcium entry this neurotransmitters are released into the synaptic cleft and
1:28
this neurotransmitters diffuses and binds to the receptor that is ligand gated receptor that is often present at the postsynaptic neuron this channel opens thus transmits the impulse and the effect may be inhibitory or excitatory depending on the type of neurotransmitter
1:48
In the case of glial cells, recent studies suggest that glial cells have many important
1:53
functions rather than just supporting neuron. It supports neurons and also provides nutrients
1:59
it is involved in positioning of neurons, regulates the activity by controlling neurotransmitter
2:05
release, controlling the oxygen level, ionic level and pH levels, it removes waste products
2:11
and protects neurons from damage. So glial cells are essential for normal and proper functioning
2:19
of neuron. Difference number three regarding the number of glial cells and neurons
2:24
As per the recent reports, the total average number of neurons in a whole brain
2:29
human brain is 86.1 billion neurons. Whereas in the case of glial cells it is around 84.6 billion
2:37
glial cells. Previously it was thought that there is 10 times more glial cells than neurons but
2:43
recent studies suggest that the ratio of glial cells to neuron is 0.99 that is close to one
2:51
The next difference is regarding the capacity of division. Neurons cannot divide once differentiated
2:57
it lacks centrioles mature neurons lacks centrioles as you see this is a neuron so this is a cell body
3:03
this is the axon that ends in axon terminal this is the dendroids so this is continuously connected
3:09
there is continuous nerve impulse transmission so actually there is no space for division once differentiated neurons cannot divide but clial cells can divide by mitosis even after differentiation Next difference is regarding the structure of neurons and glial cells All neurons
3:28
have three different parts. First one is the cell body with nucleus and all other organelles like
3:35
colgia, paratus, mitochondria etc. Then this is the dendrites that receives the signals
3:41
than this axon that sends the signals to the next neuron or transmits the signal to the next neuron
3:48
So there are glial cells like Schwann cells that protects this axon and also helps in transfer of
3:55
nerve impulse. Whereas there are different types of glial cells like astrocytes, oligodentrocytes
4:00
microglial cells etc. all are having a fibrous appearance due to thick bundles of cytoplasmic
4:06
strands and the final difference is regarding the types of neurons and
4:11
glial cells. Neurons are divided into four basic types based on the structure
4:16
unipolar neuron, multipolar neuron, bipolar neuron and pseudo unipolar neuron. Unipolar means it is having a single process or single extension that is
4:29
emerging from the cell mass or cell body. So it is having a single process or
4:35
single extension emerging from the cell body therefore called as unipolar whereas bipolar
4:40
from either sides of the cell body. An extension is that ends in either axons or oxon or dendrites
4:47
whereas multipolar neuron has many dendrites, many extensions, many dendrites and often with a single
4:55
axon that can receive multiple signals Most common neuron in humans is the multipolar neuron And finally glial cells there are different types of glial cells like astrocytes ependymal cells
5:09
oligodendrocytes, microglial cells, satellite cells and Schwann cells. Let us see the function
5:14
of each type of the cells. In the central nerve system there are astrocytes, ependymal cells
5:20
oligodendrocytes and microglial cells. Astrocytes they are so called because of the star-shaped
5:26
structure. It maintains blood-brain barrier controlling the levels of neurotransmitter around synapses, regulates ionic level and also provide metabolic support. Epidemal cells often
5:39
lines the spinal cord and ventricles of the brain. It is involved in producing cerebrospinal fluid
5:45
whereas oligodendrocytes, eight myelinate central nervous system axons provide the structural framework whereas microglial cells are the brain's immune cells. It removes dead cells
5:57
and pathogens by phagocytosis just like phagocytes like microphages in the immune system
6:04
Whereas peripheral nervous system has two types of glial cells, satellite cells and schwann cells
6:10
satellite cells that surrounds neuron cell bodies in canclea. It regulates neurotransmitter levels
6:17
whereas Schwann cells myelinate neurons in peripheral nervous system involved in maintenance
6:23
and regeneration of neurons upon injury. So these are the major functions of different types of
6:29
glial cells. So these are the major differences between neurons and glial cells. Hope you are
6:35
clear. Take care. Stay blessed. Thank you so much. You are with biology examsforay.com
