TY - CHAP M1 - Book, Section TI - Approach to the Patient with Gastrointestinal Disease A1 - Hasler, William L. A1 - Owyang, Chung A2 - Loscalzo, Joseph A2 - Fauci, Anthony A2 - Kasper, Dennis A2 - Hauser, Stephen A2 - Longo, Dan A2 - Jameson, J. Larry Y1 - 2022 N1 - T2 - Harrison's Principles of Internal Medicine, 21e AB - The gastrointestinal (GI) tract extends from the mouth to the anus and is composed of organs with distinct functions. Sphincters that assist in gut compartmentalization separate the organs. The gut wall is organized into distinct layers that contribute to regional activities. The mucosa is a barrier to luminal contents or a site for fluid and nutrient transfer. Smooth muscle in association with the enteric nervous system mediates propulsion between regions. Many GI organs possess a serosal layer that provides a supportive foundation and permits external input. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1198711238 ER -