What are similarities between the sympathetic and parasympathetic nervous system?

Answer 1

Question is short but answer is bit long. Parasympathetic system is meant for to to maintain the homeostasis and body building. Sympathetic system is meant to give you ' Fight or flight response. So you have pupils constricted in parasympathetic and dilated in sympathetic response. You need not see towards the world during first and need to look at the world carefully in danger. Secretions of gastrointestinal system are increased, peristalsis is increased, spinctures are opened up during stimulation of the parasympathetic system. This helps in digestion and body building. Vise verse is true with sympathetic system. During stimulation of the sympathetic system your cardiovascular system is on the toes, to supply more blood to muscles. So the heart rate is increased, stroke volume is increased ans as a result you have great increase in cardiac output. So cardiac output may go to 25 litres / minute from 5 litres / minutes. Blood vessels to muscles are dilated, so that almost 20 litres blood goes to muscles. Net increase from 0.5 litres to 20 litres / minute. In respiratory system you have bronchial system dilated to provide more oxygen to lungs in sympathetic stimulation, the bronchial secretions are less in amount and respiratory rate increases to high level. Vise verse is true with parasympathetic system, when you are resting and need less of the oxygen. In parasympathetic system you have contraction of urinary bladder and relaxation of the spincture to void the urine. During stress you have no time for urination and reverse is true. Erection of penis is managed by parasympathetic system and ejaculation is done by sympathetic system.

Answer 2

The sympathetic and the parasympathetic systems originate from the autonomic nervous system. The sympathetic nervous system activates under stressful situations. The parasympathetic system is in charge of the rest and digest portions of response.

Answer 3

They are both divisions of the autonomic nervous system and both help maintain hemostasis.