Foundations
How the gut makes acid, protects itself, and how the vomiting reflex and motility work.
How the Stomach Makes Acid — and Where the Drugs Act
The stomach deliberately fills itself with acid strong enough to dissolve metal, then protects its own wall from that acid. When this balance tips, you get ulcers and reflux — and almost every drug for them targets one point in a simple pathway. Learn how acid is made, and the whole acid-blocking section falls into place.
The Vomiting Reflex & Gut Motility: The Map Behind the Drugs
Why does one anti-sickness drug work brilliantly for chemotherapy but uselessly for travel sickness? Because vomiting can be triggered through several different receptors, and each drug blocks a different one. Learn this one map of the vomiting reflex, and you'll be able to pick the right antiemetic for the right cause — the single most useful idea in this whole section.
