GASTROINTESTINAL PHYSIOLOGY Ida Marie Lisle ♦ Amalie Misund First Edition May 2019 Copyright StudyAid 2019 Authors Ida Marie Lisle Amalie Misund Danielle Mellis Nilsson Illustrators Nora Charlotte Sønstebø (front page) Ida Marie Lisle Amalie Misund Booklet Disclaimer All rights reserved. No part of this book may be reproduced in any form on by an electronic or mechanical means, without permission from StudyAid. Although the authors have made every effort to ensure the information in the booklet was correct at date of publishing, the authors do not assume and hereby disclaim any liability to any part for any information that is omitted or possible errors. The material is taken from a variety of academic sources as well as physiology lecturers, but are further incorporated and summarized in an original manner. It is important to note, the material has not been approved by professors of physiology. All illustrations in the booklet are original. This booklet is made especially for students at the Jagiellonian University in Krakow by tutors in the StudyAid group (students at JU). It is available as a PDF and is available for printing. If you have any questions concerning copyrights of the booklet please contact [email protected]. About StudyAid StudyAid is a student organization at the Jagiellonian University in Krakow. Throughout the academic year we host seminars in the major theoretical subjects: anatomy, physiology, biochemistry, immunology, pathophysiology, supplementing the lectures provided by the university. We are a group of 25 tutors, who are students at JU, each with their own field of specialty. To make our seminars as useful and relevant as possible, we teach in an interactive manner often using drawings and diagrams to help students remember the concepts. In addition to most seminars we create booklets, on which the seminars are based to aid the students in following the presentations. If you have any questions, do not hesitate to contact StudyAid at www.studyaid.no, we are always happy to answer any Questions you may have academically related or not. 2 Table of contents SECTION 1 – STRUCTURE OF THE GASTROINTESTINAL TRACT ........................................................... 5 SECTION 2 – INNERVATION OF THE GASTROINTESTINAL TRACT ....................................................... 7 2.0 – EXTRINSIC INNERVATION OF THE GASTROINTESTINAL TRACT ................................................................... 7 2.1 – INTRINSIC INNERVATION OF THE GASTROINTESTINAL TRACT .................................................................... 9 2.2 – NEUROTRANSMITTER AND NEUROMODULATORS REGULATING THE GIT .................................................. 10 2.3 – REFLEXES ..................................................................................................................................... 11 2.4 – TEST YOURSELF ............................................................................................................................. 12 SECTION 3 – GASTROINTESTINAL REGULATORY SUBSTANCES ........................................................ 14 3.0 – CLASSIFICATION OF GASTROINTESTINAL SUBSTANCES. .......................................................................... 14 3.1 – GASTROINTESTINAL HORMONES ...................................................................................................... 15 3.2 – OVERVIEW OF GASTROINTESTINAL REGULATORY SUBSTANCES ............................................................... 20 3.3 – APPETITE AND SATIETY ................................................................................................................... 23 3.4 – TEST YOURSELF ............................................................................................................................. 24 SECTION 4 – GASTORINTESTINAL MOTILITY ................................................................................... 26 4.0 – MUSCLE AND CONTRACTILE TISSUE IN GIT ........................................................................................ 26 4.1 – SLOW WAVES ............................................................................................................................... 27 4.2 – CHEWING AND SWALLOWING .......................................................................................................... 28 4.3 – ESOPHAGEAL MOTILITY .................................................................................................................. 30 4.4 – GASTRIC MOTILITY ........................................................................................................................ 32 4.5 – INTESTINAL MOTILITY ..................................................................................................................... 36 4.6 – TEST YOURSELF ............................................................................................................................. 38 SECTION 5 – SECRETION ................................................................................................................ 40 5.0 – SALIVARY GLANDS ......................................................................................................................... 40 5.1 – THE STOMACH .............................................................................................................................. 42 5.2 – THE PANCREAS ............................................................................................................................. 47 5.3 – THE GALLBLADDER ........................................................................................................................ 51 5.4 – TEST YOURSELF ............................................................................................................................. 53 SECTION 6 – DIGESTION AND ABSORPTION ................................................................................... 55 6.0 – CARBOHYDRATES .......................................................................................................................... 55 6.1 – PROTEINS .................................................................................................................................... 56 6.2 – LIPIDS ......................................................................................................................................... 58 6.3 – VITAMINS .................................................................................................................................... 59 6.4 – IRON ........................................................................................................................................... 62 6.5 – TEST YOURSELF ............................................................................................................................. 63 SECTION 7 – INTESTINAL FLUID AND ELECTROLYTE TRANSPORT .................................................... 65 7.0 – FLUID bALANCE ............................................................................................................................ 65 7.1 – INTESTINAL ABSORPTION ................................................................................................................ 66 7.2 – INTESTINAL SECRETION ................................................................................................................... 69 7.3 – DIARRHEA .................................................................................................................................... 70 7.4 – TEST YOURSELF ............................................................................................................................. 72 SECTION 8 - METABOLIC FUNCTIONS OF THE LIVER ....................................................................... 74 8.0 – INTRODUCTION ............................................................................................................................. 74 8.1 – CARBOHYDRATE METABOLISM ........................................................................................................ 74 8.2 – PROTEIN METABOLISM .................................................................................................................. 75 8.3 – FAT METABOLISM ......................................................................................................................... 75 8.4 – OTHER METABOLIC FUNCTIONS ....................................................................................................... 76 8.5 – TEST YOURSELF ............................................................................................................................. 78 3 How to use this booklet This booklet is only meant as a SUPPLEMENTARY tool in your studies for the final exam. We absolutely recommend you to use other sources as well. We have tried to focus on exam relevant materials, but there is no guaranty that this will cover everything. In this booklet we have tried to break down the material of GI physiology. You will find summarizing tables, illustrations and flow charts. Use them as a supplement as you go through other materials. Last in each section there is a set of Questions, made so that you can review the material. Try to answer by yourself before you check the answer sheet. A suggestive answer sheet is provided in an additional document. Abbreviations On the exams there will be used abbreviations, so make sure you know them. Structures ENS Enteric Nervous System ECL cell Enterochromaffin-like Cell GIT Gastrointestinal Tract GI Gastrointestinal MMC