Identify the effects of the vagus nerve on the following components of the digestive system Salivary glands Pyloric sphincter (gastric emptying) Smooth muscle in the gallbladder Smooth muscle in the duodenal papilla (sphincter of Oddi)

Vagus nerve is the 10th cranial nerve. It is long start from brain and distributed over head, thorax and abdomen.

Explanation:

1.   In the salivary gland the secretory and vasodilator effect on afferent nerve is mediated mainly by parasympathetic reflex which is given by vagus nerve.

2.   Pyloric sphincter is the part present between the stomach and small intestine which regulate the flow of food particles from stomach to the intestine. Vagus nerve control the activities of pyloric sphincter. Vagus nerve help the pyloric sphincter to relax.

3.  Efferent nerves of vagus nerve help the gall bladder to contract. Vagus nerve is stimulating the gastric tract to contract. So the vagus nerve stimulation promotpromotprthe production of CCK hormone and it will lead to the contraction and secretion of hormones from the gallbladder. Those contractions will help the gallbladder to empty the hormones from gallbladder.

4.  The efferent nerves of vagus nerves act on the smooth muscles of duodenal papila. As above says it lead to the contraction of smooth muscles and also promote the production of CCK.