Question

Distention and the presence of peptide in the stomach stimulate

a. The enteric nervous system
b. Long reflex
c. hormone release that slows gastric motility
d. Release of enzymes and bicarbonate from the pancreas

Answer 1

Distention and the presence of peptides in the stomach stimulate the release of gastrin, which primarily increases gastric acid production and motility, but also indirectly affects the pancreas by triggering other hormones such as secretin, resulting in the release of bicarbonate-rich pancreatic juice and enzymes.

Step-by-step explanation:

The presence of food in the stomach causing distention and the presence of peptides stimulate several physiological responses. One important response is the release of gastrin, which is a hormone secreted by the enteroendocrine G cells in the stomach. This hormone has multiple effects, including stimulating the secretion of gastric acid by the parietal cells and enhancing smooth muscle contractions.

In addition, gastrin has effects on the pancreas. While gastrin primarily focuses on stomach functions, when the chyme (partially digested food) enters the duodenum, hormones such as secretin and cholecystokinin (CCK) are released from the duodenum to work on the pancreas. Secretin stimulates the pancreas to release a bicarbonate-rich pancreatic juice, which neutralizes the acid coming from the stomach, and CCK stimulates the secretion of pancreatic enzymes to further break down proteins and fats. Therefore, distention of the stomach, along with the presence of peptides, can stimulate the release of hormones that indirectly affect the pancreas and slow gastric motility.

Answer 2

Distention and the presence of peptides in the stomach primarily stimulate the release of gastrin from the stomach's enteroendocrine cells, which stimulates the secretion of gastric acid and affects gastric motility. Gastrin also indirectly leads to the release of enzymes and bicarbonate from the pancreas by triggering other hormones like secretin and CCK.

Step-by-step explanation:

Distention and the presence of peptide in the stomach stimulate several responses in the digestive system. When the stomach is distended, this activates stretch receptors that trigger local neural reflexes, increasing the secretion of gastric juices by releasing acetylcholine. In the context of hormonal control, distention and partially digested peptides trigger the release of the hormone gastrin from the stomach's enteroendocrine cells. Gastrin plays a crucial role by stimulating the secretion of gastric acid from the parietal cells, which is needed for the digestion of proteins. Additionally, gastrin contributes to smooth muscle contraction in the stomach.

It is important to note that the enteric nervous system is involved in the local control of gut function via short reflexes, and distention of the stomach can also initiate long reflexes that involve the central nervous system. However, when the duodenum becomes distended with chyme, the enterogastric reflex helps to inhibit further secretion and stomach motility, allowing the duodenum to process the incoming chyme effectively.

The direct answer to the student's question is that distention and the presence of peptide in the stomach primarily stimulate the release of hormones like gastrin, which can indeed slow gastric motility as part of its regulatory function. Moreover, gastrin also indirectly stimulates the release of enzymes and bicarbonate from the pancreas through the action of hormones like secretin and cholecystokinin (CCK), which are triggered when the acidic chyme enters the duodenum.