GENERAL HISTOLOGY

Detailed explanation-1: -These studies suggest that: (a) Both secretin and cholecystokinin augment pyloric sphincter pressure while gastrin I is an antagonist inhibiting their effects.

Detailed explanation-2: -Cholecystokin (CCK): CCK is secreted by the mucosa of the jejunum in response to the arrival of fats and proteins from the stomach. CCK affects the stomach: CCK decreases gastric secretion and motility and increases tone of the pyloric sphincter to reduce the rate of stomach emptying!

Detailed explanation-3: -Gastrin promotes higher stomach emptying, which in turn causes an increase of the pyloric sphincter opening intervals.

Detailed explanation-4: -As the duodenum fills, it puts pressure on the pyloric sphincter, causing it to close. The duodenum then uses peristalsis to move the chyme through the rest of the small intestine. Once the duodenum is empty, pressure on the pyloric sphincter goes away, allowing it to open again.