Nerves
Nerves are
bundles of nerve extensions of white matter in the form of string that make the
nerve centers communicate with every organ in the body. They are part of
peripheral nervous system. These
signals, often called nerve impulses, are also known as action potential.
Epineurium:
The last layer of a nerve and is composed of connective tissue cells and
collagen fibers.
Structures:
·Perineurium:
It each of the concentric layers of tissue which surrounds each of the smaller
bundles of a nerve.
·Endoneurium:
They're fine bundles of collagen fibers, along with some fibroblasts between
nerve fibers. The endoneurium is composed of fine delicate reticular fibers surrounding
each nerve fiber.
· Axolemma:
Also known as axonal membrane, surrounds the axon of the nerve fiber.
·Schwann
cells: cells able to produce the myelin that surrounds nerves.
·Oligodendrocytes:
cells able to produce the myelin that surrounds some of the nerves.
The nerve
has two essential properties: excitability and conductivity.
Excitability is the property that has the nerve
cell to acquire a molecular vibration under the action of an exciting. The cell
can be excited by a nerve center for an exciting natural light or artificial as
an exciting electric shock. The stimulus spread is called a nerve impulse, and
its passage from one point to another of the nerve fiber is the nerve
conduction. The most used is electricity because it is very easy to regulate
the intensity and duration of application.
Conductivity is the property that the peripheral
nerve to ensure the propagation of vibration along the nerve in the wave form
so that the wave is propagated in the water surface. For the exercise of the conductivity
is necessary that has not undergone any nerve degeneration and in its
trajectory have perfect continuity. In the normal nerve impulse intensity
remains constant all the way.