From Mouth to Stomach

Practice: A 20-year-old college student eats a slice of pepperoni pizza. Which of the following parts of the pizza will be (very partially) digested in her mouth?

Practice: A 45-year-old woman presents to her gastroenterologist complaining of difficulty swallowing. She reports that she often feels like food gets “stuck” in her throat, causing pain. She sometimes coughs up undigested bits of food. The gastroenterologist passes a camera into the patient’s esophagus and finds lots of food trapped at the junction between the esophagus and the stomach. Which of the following structures is likely dysfunctional in this patient?