Its action is described as being complementary to that of the sympathetic nervous system, which is responsible for stimulating activities associated with the fight-or-flight response. Nerve fibres of the parasympathetic nervous system arise from the central nervous system. Specific nerves include several cranial nerves, specifically the oculomotor nerve, facial nerve, glossopharyngeal nerve, and vagus nerve. Three spinal nerves in the sacrum (S2-4) also act as parasympathetic nerves.
A healthy BMI is considered to be between 18.5 and 24.9. Based on these BMI tables, the National Heart, Lung and Blood Institute suggests that a healthy weight range for women who are 5 feet 4 inches tall is 110 to 140 pounds.
1 Normal total weight gain for a healthy woman is 25 to 35 pounds. 2  Overweight women should gain only 10 to 20 pounds during pregnancy.  Underweight women or women with multiples (twins or more) should gain 35 to 45 pounds in pregnancy.