Which one of the following statements regarding the regulation of gastrointestinal function is true?
The salivary glands are under the influence of both the sympathetic and parasympathetic nervous system. Parasympathetic stimulation results in a more watery secretion compared with sympathetic stimulation, which produces increased amounts of protein with reduced volume. The vagus is parasympathetic, which in general is stimulatory to gastrointestinal tract. In general, sympathetics are inhibitory to the gastrointestinal tract. (The exceptions are salivary glands.)