Introduction to Psychology - Essay Example

Neurons have three structural classifications which are Dendrites, Cell body, and the Axon. The bushy Dendrite fibers are shaggy subdivisions of a neuron that receive information and conduct it towards the cell body. From there the axon fibers forward the information to other neurons or to muscles or glands. The axon has terminal fibers at its end and the message passes through these fibers from one neuron to next. After the information reaches the axon, it then moves down in the form of an electrical signal which is called action potential.

Unlike the short dendrites, axons are sometimes very long projecting several feet throughout the body. When the electrical impulse reaches the end of an axon, the information is then transmitted across the synaptic gap to the dendrites of the neighboring neuron. Synapse or synaptic gap is the gap between axon terminal of one neuron and the dendrite and cell body of receiving neuron. Sometimes, the electrical signal can bridge the gap between the neurons instantaneously and continue along its path.

Otherwise, neurotransmitters send the information from one neuron to the next. Neurotransmitters are chemical messengers that navigate the synaptic space between neurons. As the sending neuron releases the neurotransmitter, it then travels through the synapse and moves on to the receptor sites on the receiving neurons and thus it influences the neuron to produce a neural impulse. Each neuron in the Each neuron in the brain is itself a tiny gadget that has intricate functions. From hundred and thousands of other neurons, it receives signals on its dendrites and cell body.

Some of these signals are excitatory, somewhat like pushing a neuron's accelerator. Other signals are inhibitory, more like pushing its break. A particular level of stimulation called the threshold is needed to activate a neural impulse. If the excitatory signals outvote the inhibitory signals and they are more than a minimum intensity, the collective signals give rise to an action potential. The action potential transmits down the axon, which branches into junctions with thousands of other neurons and with the body's muscles and glands.

The release of neurotransmitters is activated when the action potential reaches the terminal branches of the axon. The neurotransmitter molecules take less than a second to cross the synaptic gap and attaching to receptor sited of receiving neurons. The neurotransmitter releases minute channels at the receiving site in an instant, allowing the electrically charged atoms to enter the receiving neuron and thus exciting or inhibiting its speediness to fire. Excess neurotransmitters are absorbed by the sending neuron in a procedure known as reuptake.

Neurons have three structural and functional classifications. On a structural basis the neurons are classified as Multipolar neurons, Bipolar neurons and Unipolar neurons. Multipolar neurons have one axon and several dendrites. Brain and spinal cord neurons are generally multipolar neurons. Bipolar neurons have one axon and one dendrite. These neurons are mostly found the retina of the eye, the olfactory area and the inner ear.Neurons with just one process extending from the cell body are known as unipolar neurons.

In that one process, one part acts as an axon and other part functions as a dendrite. On functional basis neurons are classified as Sensory, Motor, and inter Neurons. Sensory Neurons also called the efferent neurons takes impulses from the sense receptors in the skin, the sense organs and the large