Excessive stimulation of vagus nerve in humans may lead to:
(a) hoarse voice
(b) peptic ulcers
(c) efficient digestion of proteins
(d) irregular contractions of diaphragm.
(b) Excessive stimulation of vagus nerve in humans may lead to peptic ulcer. Vagal stimulation increases peristalsis which in excess, secretes more HCl and pepsin from stomach. These causes erosion through protective barrier of mucus and muscularis mucosa into the submucosa which leads to peptic ulcer.