Sympathetic Parasympathetic Divisions Essay

This essay has a total of 688 words and 4 pages.

Sympathetic Parasympathetic Divisions








Parasympathetic and Sympathetic Divisions

The autonomic nervous system is made up of two divisions. There are many differences
between these divisions. First of all there are anatomical and physiological differences.
The parasympathetic division of the autonomic system origin is in the craniosacral
outflow, the brain stem nuclei of cranial nerves III, VII, IX, and X; and spinal cord
segments S2-S4. The sympathetic division on the other hand is much more complex than the
parasympathetic and is originated in the thoracolumbar outflow. Also, in the lateral horn
of gray matter of the spinal cord segments of thoracic 1 to lumbar 2. Another important
physiological difference is the location of ganglia in each division. Ganglia of the
parasympathetic division are in intramural or close to the visceral organ served. The
sympathetic ganglia are located with in a few centimeters of the central nervous system.
They are also alongside the vertebral column and anterior to the vertebral column.

The relative length of preganglionic and postganglionic fibers in the parasympathetic and
sympathetic divisions is as such. The parasympathetic have long preganglionic and short
postganglionic. The sympathetic are just the opposite, short preganglionic and long
postganglionic. There is no rami communication in the parasympathetic division, while the
sympathetic division has gray and white rami communication. The functional goal of the
parasympathetic division is maintenance functions, to conserve and store energy. The
sympathetic divisionís goal is to provide the body to cope with emergencies and intense
muscular activity.

There are many effects of the parasympathetic and sympathetic divisions on various organs.
The constricting of muscles and eye pupils stimulates the iris of the eye by the
parasympathetic system. The sympathetic effects are the stimualtes of dilator muscles and
dilate the eye pupils. The parasympathetic effects of the cilliary muscle of the eye are
to stimulate muscles, which result in the bulging of the lens for accommodation and close
vision. There are no effects for the sympathetic division. The nasal lacrimal, salivary,
gastric, and pancreas glands are effected by the parasympathetic and sympathetic systems.
The parasympathetic division stimulates secretory activity, where the sympathetic division
inhibits secretory activity and causes vasoconstruction of blood vessels supplying the
glands. There is no parasympathetic effect on sweat galnds, the adrenal medulla, or the
arrector pili muscles. There are sympathetic effects though. The glands are inhibited by
secretory activity causing vasoconstruction of blood vessels supplying the glands. The
sweat glands are stimulated copious sweating. The arrector pili muscles are stimulated to
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