Classes of Neurons and Neuroglia in CNS: Structure, Function, and Associated Diseases

This essay discusses the different classes of neurons (sensory, motor, and interneurons) and their structures and functions. It also describes the six classes of neuroglia in the CNS and their functions. Additionally, it explores the diseases associated with lack of myelin, such as multiple sclerosis and transverse myelitis. The essay concludes by emphasizing the importance of CNS in communication and coordination.

Essay

Contents
INTRODUCTION...........................................................................................................................1
MAIN BODY..................................................................................................................................1
CONCLUSION................................................................................................................................5
REFERENCES................................................................................................................................6

INTRODUCTION
In this documentation, it focuses on the central nervous system and identifying its
significant role in terms of communication. In some cases, it harder for performing different
tasks and finding the causes of diseases. The essay will describe the classes of neurons and also
identifying its entire structure, functions. Furthermore, it will identify the importance of
neuroglia classes in terms of CNS and identify its functioning. However, it will be demonstrated
the different disease associated with lack of myelin.
MAIN BODY
Describe the classes of neurons and the major structures
The cells that form the nervous system and brain are known as Neurons. These are of
different types and perform special functions in the muscles, brain and spinal cord. Neurons can
be divided into three classes, namely, sensory, motor and interneurons. Sensory neurons are
those nerve cells which get activated when there is a sensory input from the environment. The
neurons which send signals to the brain and the nervous system when an individual touches a hot
surface are included in the class of sensory neurons. Neurons belonging to this class can be
activated by physical inputs such as sound, heat, touch or by chemical inputs such as taste or
smell.
Motor neurons form a part of the Central Nervous systems (CNS). These perform the
work of connecting to muscles, organs and glands in the body (Brehmer, 2021). These neurons
perform the work of transmitting impulses from spinal cord to muscles of skeletal and smooth
type. In this way, motor neurons are responsible for direct control of all the muscle movements.
The motor neurons are divided into two types, lower and upper motor neurons.
Interneurons are those that connect the motor neurons with the sensory neurons. These
perform the work of transferring signals between sensory and motor neurons. The interneurons
can also communicate with each other by developing various complex circuits.
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Major structures of neuron
The neuron comprises of four main structures namely dendrites cell body, axon and
synapse. Dendrites are branch like structures whose work is to receive messages from other
neurons and transmit them to the body of the cell. The cell body comprises of a nucleus,
endoplasmic reticulum, mitochondria, Golgi body and other components (Sardar, Saha and
Ghosh, 2022). Axon is a structure in the shape of a tube and performs the function of carrying
electric impulses from cell body to terminals of axon. Synapse is the chemical junction that is
present between the terminal of one neuron and dendrite of the other neuron.
Functions of a typical neuron
A typical neuron performs the function of chemical synapse and electrical synapse. In
chemical synapses, chemical messengers known as neurotransmitters are released by the
neurons. The neurotransmitters are molecules which after crossing the synaptic cleft bind to the
receptors in the postsynaptic ending of a dendrite (Delgado and et.al., 2022). These are capable
of triggering a response in the postsynaptic neuron which may cause it to generate its own action
potential. At other times, the neurotransmitters can prevent occurrence of an activity in the
postsynaptic neuron.
Another function of neuron is electrical synapses which are formed when a gap junction
connects two neurons. This gap is made up of ion channels and is smaller than a chemical
synapse. The ion channels assist in transmitting a positive electrical signal.
The typical function of neuron are related to the transmission of signals from one node to
another. While performing various common thing in different type of cells. It is actually
performing a functions and allows neurons to transmit both chemical as well as electrical signals.
This is the most common function in the central nervous system (CNS).
Classes of neuroglia in CNS
Neuroglia refers to the class of cells that represent the performance of physiological,
developmental as well as metabolic support for neurons. These are responsible cells for
maintaining the homeostatic control and improve the immune surveillance in the human nervous
system. Here are identified six classes of neuroglia in CNS, involves in different specialized
functions apart from the support of neurons.
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Astrocytes are shaped such as star and becoming abundant glial cell in the CNS. It has
been examined the radiating possess which is always supports to control the neurons, capillaries.
It support and brace the different neurons and anchor them to supply nutrient from one node to
another. Astrocytes control the system of chemical environment.
Microglial cells are considered the smaller in size or shape with representing a thorny
processes. Usually, it has found in the CNS, while invading the level of micro-organism. In some
cases, it is also showing a dead neurons which are present (Galkina, Vetrovoy and Eschenko,
2021). The microglial cells are helping the transformation into phagocytic and also cleaning the
neuronal debris.
Ependymal cells are situated in the central point of brain as well as spinal cord where it
has been established a barrier between cerebrospinal fluid and filled with the tissue of CNS.
Oligodendrocytes are linked with nerves and produce an insulating which has been
covered in the myelin sheath. Generally, it has found in the CNS.
Satellite cells are exist around the cell bodies of neurons. It is also representing as
concept of analogous to the astrocytes in CNS.
Schwann cells are showing in the nerve fibers and showing existence of peripheral
nervous system. The overall functionality of cell is same kind of oligodendrocytes.
Functions in the CNS
CNS stands for central nervous system is comprised with the functionality of brain and
spinal cord. Typically, CNS can be categorized into different ways: - process information,
sensory data and motor signals. These are developing a strong coordination between different
cells. The CNS can be received the signals from sensory information and helping to control the
entire body responses. Typically, the central nervous system plays an important role in terms of
receiving a proper data from every body part of human being (Gomez, Traunmüller and
Scheiffele, 2021). Therefore, it has become easier to establish a strong coordination and
collaboration in different activities, produce a better body’s responses.
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The central nervous system can be differentiated from the peripheral nervous system. It
should be consider all kind of nerves outside of spinal cord as well as brain. It can easily carrying
the messages to CNS. At every situation, CNS plays an important role in which handle the entire
body functions, work together to take in the information or data. It control to respond the body in
proper manner.
Diseases associated with lack of myelin
A lack of myelin can be representing the neurological based deficits such as changing the
vision, altered sensation, feeling weakness and cognitive or behavioral problems. These kind of
situation arise so that it is important to identify de-myelinating diseases affect the brain as well as
spinal cord. On the other hand, it is also examined that condition of peripheral nerves that shows
a bunch out from the spinal cord and brain (McCubbin, Harrison and Cooper, 2022). Due to lack
of myelin, the most common disease occurs such as multiple sclerosis. It is also considered the
serious disorder which is directly affecting the immune system and produce large amount of
fluid, difficult to control or maintain in proper manner. On the other hand, Transverse myelitis is
another kind of disease which shows an inflammation of both side of section in the spinal cord. It
is extremely caused by lack of myelin. Every day, it has been diagnosed a new cases and people
experiencing different symptoms, disability. As a result, it will be showing a critical condition or
situation.
ADEM (Acute disseminated encephalomyelitis) refers to the inflammation and
representing some kind of changes in human body like swelling. It is directly affecting the cells
of myelin in spinal cord, brain. It is something that affects the optic nerves.
Neuromyelitis optica is kind of disease which is mainly affecting the eyes, spinal cord. In
some cases, it also developed the possibilities to affect the brain functions. It is rarer serious
disease and affecting large number of population in United Kingdom. On the basis of discussion,
it has been examined that each and every diseases occurs due to the lack of myelin. Usually, it
will be affecting the central nervous system (CNS). When it is thinking about the myelin, it is an
essential aspect to insult the layer of proteins, lipids that should covered with multiple nerves.
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CONCLUSION
In above analysis, it has concluded that central nervous system (CNS) is the most
important part of human body because all kind of signals passed from one node to another. This
can be possible only through CNS and easily managing, controlling the body functions. In this
documentation, it has been summarized the different classes of neurons and also identifying its
entire structure, functions. Furthermore, it can be analysed the classes of neuroglia, maintaining a
coordination between brain as well as spinal code. The possibility to handle the role of CNS and
performed different functions. However, it has been examined the different disease associated
with lack of myelin.
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REFERENCES
Journals and Books
Brehmer, A., 2021. Classification of human enteric neurons. Histochemistry and Cell Biology.
156(2). pp.95-108.
Delgado, R.N. and et.al., 2022. Individual human cortical progenitors can produce excitatory and
inhibitory neurons. Nature. 601(7893). pp.397-403.
Galkina, O.V., Vetrovoy, O.V. and Eschenko, N.D., 2021. The Role of Lipids in Implementing
Specific Functions in the Central Nervous System. Russian Journal of Bioorganic
Chemistry. 47(5). pp.1004-1013.
Gomez, A.M., Traunmüller, L. and Scheiffele, P., 2021. Neurexins: molecular codes for shaping
neuronal synapses. Nature Reviews Neuroscience. 22(3). pp.137-151.
McCubbin, S., Harrison, D.A. and Cooper, R.L., 2022. Glia Excitation in the CNS Modulates
Intact Behaviors and Sensory-CNS-Motor Circuitry. Neuroglia. 3(1). pp.23-40.
Sardar, S., Saha, N. and Ghosh, A., 2022. Microglia, the Sentinel of Brain in the Evolution of
Nervous System from Invertebrate to Vertebrate: A Short Review. Journal of Scientific
Research. 14(2). pp.685-697.
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