1. By: Safana Sadiq

2. 
The digestive system is controlled by both:
 Nerves, and
 Hormones

3. Neuronal control of
digestion

Autonomic Nervous System
SNS PNS
Digestive system Digestive system activity
activity

4. Sympathetic nerves that regulate digestion are:

 The greater splanchnic nerves
 The lumbar splanchnic nerves, and
 The sacral splanchnic nerves

5. 
The parasympathetic nerve that regulates
digestion are the vagus nerves.

6. Hormones that control digestion are:

 Gastrin
 Secretin
 Cholecystokinin
 Glucose insulinotropic peptide (GIP)

7. Effects of gastrin

 Stimulates gastric juice secretion
 Stimulates smooth muscle contraction
 Relaxation of pyloric sphincter

8. Effects of secretin

 Stimulates bicarbonate secretion
 Stimulates bile production
 Inhibits gastric juice secretions and gastric motility

9. Effects of cholecystokinin

 Stimulates bile release
 Stimulates pancreatic juice secretion
 Relaxation of the hepatopancreatic ampulla and
opening of hepatopancreatic sphincter

10. Effects of GIP

 Stimulates the pancreas to begin release of insulin

11. The 3 phases of digestive
regulation

 Cephalic phase
 Gastric phase
 Intestinal phase

12. Cephalic Phase

 Neuronal response:
Stimuli that arouse digestion relayed to
hypothalamus
Nerve impulse initiated in vagus nerve
Impulse innervates nerve network of GI tract
Contraction of sm ms & secretion of gastric juice
promoted

13. Gastric Phase

The stimuli that initiates gastric phase includes:
 Distension of the stomach
 Low acidity
 Presence of peptides

14. Gastric Phase

 Neural response: gastric juice secretion & smooth
muscle contraction promoted
 Hormonal response: gastrin production promoted
 General effect: stomach and small intestine prepare
for digestion of chyme , and gastric emptying is
promoted

15. Intestinal Phase

 Neural response:
 gastric secretion & gastric motility are inhibited
 Intestinal secretion, sm ms contraction, bile &
pancreatic juice production are promoted

16. Intestinal Phase

 Hormonal response: production of secretin, CCK &
GIP is promoted
 General effects : gastric emptying is retarded to
allow adequate time for digestion in the SI. And
intestinal digestion and motility are promoted.

17. Reference

http://www.cliffsnotes.com/study_guide/t
opicArticleId-277792,articleId-27770.html
http://www.aboutgastro.com/digestive-
system/regulation-of-digestive-process