Nerve cells are also called neurons. There are 3 types of
neurons - sensory, motor and association neurons.
Sensory neurons have sensitive nerve endings called
receptors.
Sensory nerves are nerves which pass message to the brain
and motor nerves are nerves which pass messages from the brain.
Association neurons are in the brain and the spinal cord.
They interpret the messages and pass them on to motor neurons.
Each neuron has a cell body which contains nucleus and
strands called nerve fibers.
There are 2 types of fibers –
Dendrites carry information to the cell body and Axons carry
information away from the cell body. The axons of 1 cell joins to another cell’s dendrites or a
muscle to pass on information.
Nerves
are cords that that contain bundles of nerve fibers Sensory nerves have
sensory neurons and motor nerves have motor neurons. Only mixed nerves have fibers from both. The spinal cord is a thick bundle of nerves, which runs from
the brain down in your backbone. Impulses from all parts of the body pass
through the spinal cord.
Information
moves all along neurons in the form of electrical signals called nerve
impulses. When an impulse reaches between one neuron and the next, a chemical
called neurotransmitter is released. If enough of this chemical builds up in
the next neuron, an impulse is sent on.
There
are 2 types of actions – Voluntary and involuntary actions.
Voluntary
actions are actions which are under our control like kicking a ball. We are
conscious of it.
Involuntary
actions are actions which are beyond our control like beating of the heart. We
are unconscious about it.
In
nervous system both brain and spinal cord pass messages through motor nerves.
The spine or the spinal cord only gives messages when there is a sudden action
like when you touch a cactus the reflex action is “OUCH”!
Reflex
actions are involuntary actions. They are usually sudden movements, such as
pulling your hand when you touch something hot. You become aware of them
because of the impulses that are sent to the brain to tell you what is
happening.
I
hope I helped you understand a few things about our nervous system
©
Samruddhhi Kotecha
