Concept #1: Enteric Nervous System and Short vs. Long Reflexes
Concept #2: The Gastrointestinal Reflexes
Concept #3: The GI Peptides-- GIP, GLP-1, CCK, Leptin, Ghrelin
Practice: A 20-year-old undergraduate brings a pepperoni pizza to share with her study group. One study group member’s mouth starts watering and stomach starts rumbling at the mere sight and smell of the pizza (i.e. before he even takes a bite). Which of the following explains his salivation and increased GI motility before eating anything?
Practice: A 20-year-old man presents to his primary-care physician complaining of frequent defecation. He reports that he always has to leave the dinner table immediately after meals to use the bathroom, which is starting to get inconvenient and embarrassing (he’s been dating a lot recently). Which of the following reflexes is causing this sudden urge to defecate after meals?
Practice: A 25-year-old medical student has a date scheduled for 7pm. It is currently 5pm and he is ravenously hungry, but doesn’t want to ruin his appetite for the date (they’re going to a delicious, romantic Italian restaurant). He decides to eat a small snack. Which of the following foods should he avoid if he wants to eat something but still wants to feel hungry for his date in two hours? (Hint: Think about the stimuli that cause the release of the various GI peptides.)