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 contract and produce goosebumps.
The parasympathetic division decreases the rate of the heart and slows it down. The sympathetic division increases the rate and force of the heart. The bladder in both divisions is opposite once again. In the parasympathetic of the bladder, the contraction of smooth muscle and the relaxation in the sympathetic division. The parasympathetic constricts for the bronchioles of the lungs, where the bronchioles are dilated in the sympathetic. The liverís sympathetic effect is in epinephrine stimulus of the liver to release glucose to the blood. There is no parasympathetic effect of the liver. In the parasympathetic division the gallbladder contracts to expel bile. In the sympathetic division the gallbladder is relaxed. The parasympathetic division causes the penis and vagina to vasodilateor erect. The sympathetic division causes the penis to ejaculate and the vagina to contract. There is little or no effect of the blood vessels in the parasympathetic division. The sympathetic division constricts most vessels and increases the blood pressure. It also constricts vessels of abdominal viscera and skin to divert blood to muscles, brain, and heart when necessary. The cellular metabolism of the sympathetic division is to increase coagulation. Sympathetic effects; adipose tissue by lipolysis, and mental activity by increasing oneís alertness.
I found the assignment a little different then most papers I have written do to one fact. I found that I could not put what the book said into my own words. I donít have a wide anatomical vocabulary, so I found that I had to copy a lot of what the book said. I am sure this is similar to some students in the class.









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