Question

which of the following statements regarding the autonomic nervous system is not true?
a the parasympathetic branch slows down the heart rate.
b the sympathetic branch dilates airways.
c the parasympathetic branch inhibits digestion.
d the sympathetic branch raises blood pressure.

Explanation:

• The parasympathetic branch is associated with the "rest - and - digest" response. It actually promotes digestion (e.g., by increasing salivation, promoting peristalsis), not inhibits it.
• The parasympathetic branch slows down the heart rate (A is true).
• The sympathetic branch is associated with the "fight - or - flight" response. It dilates airways (to increase oxygen intake, B is true) and raises blood pressure (by constricting blood vessels in non - essential organs and increasing cardiac output, D is true).

Answer:

C. The parasympathetic branch inhibits digestion.