TY - CHAP M1 - Book, Section TI - Approach to the Patient with Gastrointestinal Disease A1 - Hasler, William L. A1 - Owyang, Chung A2 - Jameson, J. Larry A2 - Fauci, Anthony S. A2 - Kasper, Dennis L. A2 - Hauser, Stephen L. A2 - Longo, Dan L. A2 - Loscalzo, Joseph PY - 2018 T2 - Harrison's Principles of Internal Medicine, 20e AB - The gastrointestinal (GI) tract extends from the mouth to the anus and is composed of several organs with distinct functions. Specialized 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. Gut smooth muscle in association with the enteric nervous system mediates propulsion from one region to the next. 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 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1160015122 ER -