Gastrointestinal | Gastric Secretion: The Cephalic & Gastric Phase

Official Ninja Nerd Website: https://ninjanerd.org Ninja Nerds! In this lecture, Professor Zach Murphy discusses the regulation of gastric secretion, focusing on the cephalic and gastric phases of digestion. We begin with the cephalic phase, which is initiated before food even enters the stomach and is triggered by the sight, smell, taste, or thought of food. Here, vagal stimulation plays a central role, releasing acetylcholine to activate parietal cells for hydrochloric acid secretion, chief cells for pepsinogen release, and G cells for gastrin secretion, priming the stomach for incoming food. We then move into the gastric phase, which begins once food enters the stomach and accounts for the majority of gastric secretions. This phase is driven by both neural and hormonal mechanisms: distension of the stomach activates local myenteric reflexes and vagovagal reflexes, while peptides and amino acids in the lumen stimulate gastrin release. Gastrin further enhances acid secretion and promotes gastric motility, creating an optimal environment for protein digestion. Enjoy the lecture and support us below! 🌐 Official Links Website: https://www.ninjanerd.org Podcast: https://podcast.ninjanerd.org Store: https://merch.ninjanerd.org 📱 Social Media   / ninjanerdlectures     / ninjanerdlectures     / ninjanerdlectures   https://x.com/ninjanerdsci/   / ninja-nerd   💬 Join Our Community Discord:   / discord   #ninjanerd #GastricSecretion #Gastrointestinal