Which of the following hormones increases gastric motility?

Gastrin is the hormone that increases gastric motility, making it the correct answer. It is produced by G cells in the stomach in response to food entering the stomach and stimulates the gastric muscle contractions, promoting the movement and mixing of food with gastric juices. This increased motility is crucial for proper digestion as it facilitates the breakdown of food and the absorption of nutrients.

In contrast, somatostatin primarily inhibits gastric motility and secretion, thereby playing a role in regulating digestive processes. Insulin, while important for glucose metabolism, does not have a direct effect on gastric motility. Glucagon, which raises blood glucose levels by promoting glycogen breakdown, also does not enhance gastric motility and instead can suppress gastrointestinal activity. Understanding the specific roles of these hormones highlights why gastrin is the main hormone responsible for increasing gastric motility.