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Digestive System 2

Digestive System II: In this lecture, Professor Diamond moves in depth into the digestive system, discussing the tongue, salivary glands, layers of the digestive track, esophagus, stomach, and small intestine. She discusses the components of the tongue, including the taste buds, and describes the tongue’s function in mixing food with saliva and amylase enzymes, swallowing, and talking. Professor Diamond goes on to describe how saliva is generated and transmitted into the mouth. She transitions to a discussion of the layers in the digestive track, including mucosa, submucosa, muscularis, and serosa. She discusses the peritoneal cavity and how the stomach and intestine are positioned in this space. Next, she describes the esophagus and how it transitions from skeletal muscle to smooth muscle as it goes towards the stomach. She moves on to discuss the stomach itself, its position, and how the pyloric valve regulates the rate at which food is passed to the intestine. She describes the stomach’s functions: mixing food with digestive enzymes, beginning protein digestion, and passing the chime (food and enzyme combination) to the intestine. She concludes with a description of how the stomach’s gastric glands facilitate digestion by secreting mucus, hydrochloric acid, and pepsinogin, resulting in the creation of pepsin, which digests proteins.