bicarbonate of soda: a white soluble compound (NaHCO3) used in effervescent drinks and in baking powders and as an antacid
bicarbonate: a salt of carbonic acid (containing the anion HCO3) in which one hydrogen atom has been replaced; an acid carbonate
parasympathetic nervous system: originates in the brain stem and lower part of the spinal cord; opposes physiological effects of the sympathetic nervous system: stimulates digestive secretions; slows the heart; constricts the pupils; dilates blood vessels