Explain the roles of acetylcholine and grp in gastrin secretion?

Acetylcholine and GRP stimulates and increase the gastrin secretion in the stomach.

Explanation:

Acetylcholine can acts as a neurotransmitter as well as hormone. The parasymapthetic nerves release acetylcholine that stimulates the release of gastrin secretion in the stomach and helps in the process of digestion.

Gastrin releasing peptide (GRP) acts as a regulatory molecule of the gastrin. GRP is a neuropeptide hormones that helps in the secretion of gastrin by stimulating the G cells of the stomach.

Thus, both GRP and acetylcholine stimulates the gastrin secretion.

fumikage isn't really a bird, and tsuyu does have teeth. tsuyu has a transformation quirk which still allows her to be partially human. otherwise we'd have a large frog running around. fumikage has teeth because again, he isn't a bird. his head was a quirk mixture if i'm correct.