Final answer:
The hormone responsible for inhibiting gastric muscle activity and slowing the emptying of the stomach into the duodenum is called gastric inhibitory peptide. This hormone decreases both stomach acid production and peristalsis, allowing for longer digestion times of fatty foods.
Step-by-step explanation:
The hormone that inhibits gastric muscle, slowing passage of food into the duodenum, is called gastric inhibitory peptide. This hormone is secreted by the small intestine in response to the presence of fatty acids and sugars. Its role is to inhibit acid production and slow down peristalsis, which is the coordinated contraction and relaxation of intestinal muscles, in order to provide more time for digestion and absorption of fatty foods.
Gastric inhibitory peptide is one of the hormones involved in the intestinal phase of gastric secretion. It works alongside other hormones such as secretin, which stimulates the pancreas to produce a bicarbonate-rich secretion, and cholecystokinin (CCK), which encourages the secretion of digestive enzymes and bile. These hormones are crucial in hormonal control during the digestive process and are secreted by specialized cells known as endocrinocytes located in the mucosal epithelium of the stomach and small intestine.