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Neurons
are the specialized cells of the nervous system. The neurons are responsible for the
transmission of electrical impulses to and from the central nervous system. The main
structures of the neuron are, the cell body, the axon, and the dentrite. Each neuron is
equipped with hundreds of dentrites, but only one axon. This places an enormous importance
on the axon. The synaptic cleft is also an important feature of neurons. The synaptic
cleft is a region of the neuron. It is the area between neurons. This region is
responsible for the separation of neurons. The neuron is composed of dentrites, the soma,
the axon, and a cell body. The cell body contains the normal organelles; such as
mitochondria and the endoplasmic reticulum. The size of neurons differs, but neurons
usually range from two to five hundred microns in diameter.
Other then
neurons there are a few other cells which are particular to the nervous system. For
example, ganglia are small bodies of cell bodies located within the nervous system.
Ganglion are primarily found in the peripheral nervous system. Tracts are another
formation found within the nervous system. Tracts are bundles of nerve fibers also know as
neuron processes. Tracts primarily run throughout the peripheral nervous system.
One of the more
important features of the neuron, is the Schwann Cell. The Schwann cell is responsible for
three jobs; the enclosing of the axon, the insulation of the axon, and the protection of
the axon. The Schwann Cell accomplishes its responsibility to the axon through the myelin
sheath. The myelin sheath is a process formed by the Schwann Cell, protecting, insulating,
and enclosing the axonal cylinder. Schwann Cells are formed by a white matter. The white
matter of Schwann Cells is actually fatty matter in a liquid state. The white matter of
Schwann Cells encloses and insulates the axonal cylinder. The thickness of the white
matter varies. The white matter of the Schwann cell id the main component of the myelinal
sheath.
The axon is the most
important section of the neuron. The main purpose of the neuron is to allow a transmission
of a message from one cell to another. This transmission would never occur, had there not
be the axon. The axon is the long finger like projection of the neural body, the cell body
of the neuron. The axon is composed of two principal sections; the axonal ending and the
Schwann Cell. The axon is covered by the Myelinal Sheath.
The axonal terminal is the ending of the axonal process. The axonal
terminal is also called the neuropodium. The axonal ending is characterized by a bulged
ending. The purpose of the axonal terminal is to carry the bulk load of the
neurotransmitters. Once the polarized impulse has reached the axonal terminal, a chemical
reaction takes place within the axonal terminal. The purpose of the chemical reaction is
to release the neurotransmitters.
Neurotransmitters are chemical substances found within the neuropodium. The purpose of the
neurotransmitter is to aid in the transmission of the nervous impulse. The electrical
impulse is not capable in diffusing across the synapse. Due to a lacking capabilities of
the nervous impulse, a large burden is place on the neurotransmitter. The synapse is the
area located between the neurons. Neurons are not connected or closely packed together, as
in other tissues of the body. All communication between neurons takes place within the
synapse. All nerve impulses must travel across the synaptic gap. The neurotransmitter is
the chemical substance which accomplishes the task of crossing the synaptic gap.
The dentrite is
another section of the neuron which aids in the nervous transmission. The dentrite is one
of the many cytoplasmic branches of the neural body. The dentrite aids in transmission by
conducting and receiving terminations of neurons. The dentrites are also responsible for
receiving impulses from neurotransmitters. Dentrites are characterized as stretching out
across the synapse. Dentrites are also known as dentrite processes.