National Cancer Institute at the National Institutes of Health
Seer Training Modules: Introduction to the Digestive System
Self-guided learning activity where students learn about the structure and function of the human digestive system. There is a short quiz at the end of the lesson to check for understanding.
OpenStax
Open Stax: Anatomy & Physiology: The Mouth, Pharynx, and Esophagus
Describe the structures of the mouth, including its three accessory digestive organs: the mouth, pharynx, and esophagus. Also trace the pathway food follows from ingestion into the mouth through release into the stomach.