Free online courseGastrointestinal Physiology

Course Description

Build a clear, exam-ready understanding of how the gastrointestinal system works from the first step of digestion to liver metabolism and intestinal motility. This free online course guides you through the core physiology that links structure to function, helping you connect everyday clinical symptoms with the underlying mechanisms in the mouth, stomach, intestines, and hepatobiliary system.

You will start with foundational concepts of oral physiology, including tooth structure, salivation, and the early stages of carbohydrate digestion. From there, you will follow the path of food through swallowing and into the stomach, learning how gastric secretion is regulated across phases and what signals stimulate or inhibit acid production. The course then expands into the liver, exploring key elements of histology and circulation, why blood supply matters for hepatic function, and how the liver manages nutrients in the fed state through hormonal regulation.

To connect physiology with real-world health and pharmacology, you will also examine biotransformation pathways that help the body process drugs and toxins, along with the logic of bile synthesis, bile acids, and transport mechanisms. By understanding bile’s role in lipid digestion and how jaundice can arise from different disruptions, you will gain a practical framework for interpreting common lab patterns and symptoms.

Finally, the course ties everything together with gastrointestinal motility across the esophagus, small intestine, and large intestine, including how mixing, propulsion, and absorption are coordinated. You will also explore neural and hormonal control, such as the enteric nervous system and hormones like CCK, and revisit digestion in an integrated way—covering carbohydrates, lipids, and proteins from initiation to breakdown and absorption. Short exercises throughout reinforce recall and help you study efficiently for health and physiology coursework.