Digestive System Part 3(The Large Intestine) the Large Intestine Is the Terminal Part of the Alimentary Canal
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General Principles of GIT Physiology Objectives
General Principles of GIT Physiology Objectives: ❖ Physiologic Anatomy of the Gastrointestinal Wall. ❖ The General & Specific Characteristics of Smooth Muscle. ❖ Neural & Hormonal Control of Gastrointestinal Function. ❖ Types of Neurotransmitters Secreted by Enteric Neurons. ❖ Functional Types of Movements in the GIT. ❖ Gastrointestinal Blood Flow "Splanchnic Circulation". ❖ Effect of Gut Activity and Metabolic Factors on GI Blood Flow. Done by : ➔ Team leader: Rahaf AlShammari ➔ Team members: ◆ Renad AlMigren, Rinad Alghoraiby ◆ Yazeed AlKhayyal, Hesham AlShaya Colour index: ◆ Turki AlShammari, Abdullah AlZaid ● Important ◆ Dana AlKadi, Alanoud AlEssa ● Numbers ◆ Saif AlMeshari, Ahad AlGrain ● Extra َ Abduljabbar AlYamani ◆ َوأن َّل ْي َ َس ِلْ ِْلن َسا ِنَ ِإََّلَ َما َس َع ىَ Gastrointestinal System: GIT Gastrointestinal System Associated Organs (Liver,gallbladder,pancreas,salivary gland) Gastrointestinal Function: ● The alimentary tract provides the body with a continual supply of water, electrolytes, and nutrients. To achieve this function, it requires: 1 Movement of food through the alimentary tract (motility). 2 Secretion of digestive juices and digestion of the food. 3 Absorption of water, various electrolytes, and digestive products. 4 Circulation of blood through the gastrointestinal organs to carry away the absorbed substances. ● Control of all these functions is by local, nervous, and hormonal systems. The Four Processes Carried Out by the GIT: 2 Physiologic Anatomy of the Gastrointestinal Wall ● The following layers structure the GI wall from inner surface outward: ○ The mucosa ○ The submucosa ○ Circular muscle layer ○ longitudinal muscle layer Same layers in Same layers Histology lecture Histology ○ The serosa. ● In addition, sparse bundles of smooth muscle fibers, the mucosal muscle, lie in the deeper layers of the mucosa. The General Characteristics of Smooth Muscle 1- Two Smooth Muscle Classification: Unitary type ● Contracts spontaneously in response to stretch, in the Rich in gap junctions absence of neural or hormonal influence. -
Autonomic Dysfunction in Cystic Fibrosis
JOURNAL OF THE ROYAL SOCIETY OF MEDICINE Supplement No. 43 Volume 96 2003 Autonomic dysfunction in cystic fibrosis AMirakhur MB MRCP MJWalshaw MD FRCP J R Soc Med 2003;96(Suppl. 43):11–17 SECTION OF PAEDIATRICS & CHILD HEALTH, 26 NOVEMBER 2002 INTRODUCTION thetic nervous system, has both pre- and postganglionic The autonomic nervous system (ANS) is a complex neural fibres. However, in general, the preganglionic fibres pass network largely responsible for the regulation of visceral uninterrupted to the organ that is to be controlled; function and maintenance of homeostasis of the internal postganglionic neurons are located in the wall of the organ.3 environment.1 This is achieved primarily through interac- The neurotransmitter for all preganglionic and para- tions with the endocrine system and via autonomic reflexes. sympathetic postganglionic fibres is acetylcholine. All The latter comprise specialized sensory receptors in the postganglionic sympathetic nerves are adrenergic except viscera which provide information regarding visceral for those fibres innervating the sweat glands which are function to higher ANS centres in the brain. At these sites cholinergic.1 sensory information is processed and integrated, and appropriate autonomic motor responses to the viscera are Higher centres relayed through the ANS efferent system. In many The supraspinal integration of ANS function is accomplished circumstances, the ANS reflexes are capable of responding by a complex interaction of many brainstem, mesencephalic very quickly to alterations in the internal environment and and cortical areas, the hypothalamus being the principal can rapidly return the system to its homeostatic baseline. higher centre for integration of ANS function. It receives sensory afferents as well as connections from the limbic GENERAL ANATOMICAL ORGANIZATION system and sensorimotor cortex, and exerts its effects via The ANS has two major divisions: the sympathetic and interactions with the endocrine system and through 2 parasympathetic nervous systems. -
Current Strategies in the Management of Irritable Bowel Syndrome
icine- O ed pe M n l A a c n c r e e s t s n I Internal Medicine: Open Access Randall et al., Intern Med 2014, S1:006 DOI: 10.4172/2165-8048.S1-006 ISSN: 2165-8048 Review Article Open Access Current Strategies in the Management of Irritable Bowel Syndrome Randall CW1,2*, Saurez AV3 and Zaga-Galante J3 1Clinical Professor of Medicine, University of Texas Health Science Ctr, San Antonio, USA 2CEO, Gastroenterology Research of America, USA 3Anahuac University, Mexico City, Mexico *Corresponding author: Charles W Randall, Clinical Professor of Medicine, University of Texas Health Science Ctr, San Antonio, USA and CEO, Gastroenterology Research of America, USA, Tel: (210) 410 2515; E-mail: [email protected] Rec date: Jan 17, 2014, Acc date: Feb 28, 2014, Pub date: Mar 09, 2014 Copyright: ©2014 Randall CW, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Irritable bowel syndrome (IBS) is one of the most studied and discussed problems in the field of gastroenterology, yet it often remains perplexing to both clinicians and patients. Some of the apprehension comes from a void of objective data that defines a diagnosis in most disorders. This level of comfort is not appreciated in the evaluation of IBS, where the art of medicine and subjective impressions are the cornerstones of proper assessment. Though this paper focuses on management, a review of pathophysiology and specific guidelines establishing a diagnosis of IBS will be addressed. -
Vestibule Lingual Frenulum Tongue Hyoid Bone Trachea (A) Soft Palate
Mouth (oral cavity) Parotid gland Tongue Sublingual gland Salivary Submandibular glands gland Esophagus Pharynx Stomach Pancreas (Spleen) Liver Gallbladder Transverse colon Duodenum Descending colon Small Jejunum Ascending colon intestine Ileum Large Cecum intestine Sigmoid colon Rectum Appendix Anus Anal canal © 2018 Pearson Education, Inc. 1 Nasopharynx Hard palate Soft palate Oral cavity Uvula Lips (labia) Palatine tonsil Vestibule Lingual tonsil Oropharynx Lingual frenulum Epiglottis Tongue Laryngopharynx Hyoid bone Esophagus Trachea (a) © 2018 Pearson Education, Inc. 2 Upper lip Gingivae Hard palate (gums) Soft palate Uvula Palatine tonsil Oropharynx Tongue (b) © 2018 Pearson Education, Inc. 3 Nasopharynx Hard palate Soft palate Oral cavity Uvula Lips (labia) Palatine tonsil Vestibule Lingual tonsil Oropharynx Lingual frenulum Epiglottis Tongue Laryngopharynx Hyoid bone Esophagus Trachea (a) © 2018 Pearson Education, Inc. 4 Visceral peritoneum Intrinsic nerve plexuses • Myenteric nerve plexus • Submucosal nerve plexus Submucosal glands Mucosa • Surface epithelium • Lamina propria • Muscle layer Submucosa Muscularis externa • Longitudinal muscle layer • Circular muscle layer Serosa (visceral peritoneum) Nerve Gland in Lumen Artery mucosa Mesentery Vein Duct oF gland Lymphoid tissue outside alimentary canal © 2018 Pearson Education, Inc. 5 Diaphragm Falciform ligament Lesser Liver omentum Spleen Pancreas Gallbladder Stomach Duodenum Visceral peritoneum Transverse colon Greater omentum Mesenteries Parietal peritoneum Small intestine Peritoneal cavity Uterus Large intestine Cecum Rectum Anus Urinary bladder (a) (b) © 2018 Pearson Education, Inc. 6 Cardia Fundus Esophagus Muscularis Serosa externa • Longitudinal layer • Circular layer • Oblique layer Body Lesser Rugae curvature of Pylorus mucosa Greater curvature Duodenum Pyloric Pyloric sphincter antrum (a) (valve) © 2018 Pearson Education, Inc. 7 Fundus Body Rugae of mucosa Pyloric Pyloric (b) sphincter antrum © 2018 Pearson Education, Inc. -
The Digestive System Overview of the Digestive System • Organs Are Divided Into Two Groups the Alimentary Canal and Accessory
C H A P T E R 23 The Digestive System 1 Overview of the Digestive System • Organs are divided into two groups • The alimentary canal • Mouth, pharynx, and esophagus • Stomach, small intestine, and large intestine (colon) • Accessory digestive organs • Teeth and tongue • Gallbladder, salivary glands, liver, and pancreas 2 The Alimentary Canal and Accessory Digestive Organs Mouth (oral cavity) Parotid gland Tongue Sublingual gland Salivary glands Submandibular gland Esophagus Pharynx Stomach Pancreas (Spleen) Liver Gallbladder Transverse colon Duodenum Descending colon Small intestine Jejunum Ascending colon Ileum Cecum Large intestine Sigmoid colon Rectum Anus Vermiform appendix Anal canal Figure 23.1 3 1 Digestive Processes • Ingestion • Propulsion • Mechanical digestion • Chemical digestion • Absorption • Defecation 4 Peristalsis • Major means of propulsion • Adjacent segments of the alimentary canal relax and contract Figure 23.3a 5 Segmentation • Rhythmic local contractions of the intestine • Mixes food with digestive juices Figure 23.3b 6 2 The Peritoneal Cavity and Peritoneum • Peritoneum – a serous membrane • Visceral peritoneum – surrounds digestive organs • Parietal peritoneum – lines the body wall • Peritoneal cavity – a slit-like potential space Falciform Anterior Visceral ligament peritoneum Liver Peritoneal cavity (with serous fluid) Stomach Parietal peritoneum Kidney (retroperitoneal) Wall of Posterior body trunk Figure 23.5 7 Mesenteries • Lesser omentum attaches to lesser curvature of stomach Liver Gallbladder Lesser omentum -
Gastrointestinal Motility Physiology
GASTROINTESTINAL MOTILITY PHYSIOLOGY JAYA PUNATI, MD DIRECTOR, PEDIATRIC GASTROINTESTINAL, NEUROMUSCULAR AND MOTILITY DISORDERS PROGRAM DIVISION OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION, CHILDREN’S HOSPITAL LOS ANGELES VRINDA BHARDWAJ, MD DIVISION OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION CHILDREN’S HOSPITAL LOS ANGELES EDITED BY: CHRISTINE WAASDORP HURTADO, MD REVIEWED BY: JOSEPH CROFFIE, MD, MPH NASPGHAN PHYSIOLOGY EDUCATION SERIES SERIES EDITORS: CHRISTINE WAASDORP HURTADO, MD, MSCS, FAAP [email protected] DANIEL KAMIN, MD [email protected] CASE STUDY 1 • 14 year old female • With no significant past medical history • Presents with persistent vomiting and 20 lbs weight loss x 3 months • Initially emesis was intermittent, occurred before bedtime or soon there after, 2-3 hrs after a meal • Now occurring immediately or up to 30 minutes after a meal • Emesis consists of undigested food and is nonbloody and nonbilious • Associated with heartburn and chest discomfort 3 CASE STUDY 1 • Initial screening blood work was unremarkable • A trial of acid blockade was started with improvement in heartburn only • Antiemetic therapy with ondansetron showed no improvement • Upper endoscopy on acid blockade was normal 4 CASE STUDY 1 Differential for functional/motility disorders: • Esophageal disorders: – Achalasia – Gastroesophageal Reflux – Other esophageal dysmotility disorders • Gastric disorders: – Gastroparesis – Rumination syndrome – Gastric outlet obstruction : pyloric stricture, pyloric stenosis • -
Gastrointestinal Motility
Gastrointestinal Motility H. J. Ehrlein and M.Schemann 1. Motility of the stomach Anatomic regions of the stomach are the fundus, corpus (body), antrum and pylorus. The functional regions of the stomach do not correspond to the anatomic regions. Functionally, the stomach can be divided into the gastric reservoir and the gastric pump (Fig. 1). The gastric reservoir consists of the fundus and corpus. The gastric pump is represented by the area at which peristaltic waves occur: it includes the distal part of the corpus and the antrum. Due to different properties of the smooth muscle cells the gastric reservoir is characterised by tonic activity and the gastric pump by phasic activity. AB Gastric reservoir Fundus tonic contractions Pylorus Corpus Antrum Gastric pump phasic contractions Figure 1 . The stomach can be divided into three anatomic (A) and two functional regions (B) 1.1 Function of the gastric reservoir At the beginning of the 20 th century it was already observed that with increasing volume of the stomach the internal pressure of the stomach increases only slightly. In dogs, for instance, the increase in pressure is only 1.2 cm of water/100 ml volume. The small increase in gastric pressure indicates that the stomach does not behave like an elastic balloon but that it relaxes as it fills. Three kinds of gastric relaxation can be differentiated: a receptive, an adaptive and a feedback-relaxation of the gastric reservoir. The receptive relaxation consists of a brief relaxation during chewing and swallowing. The stimulation of mechano-receptors in the mouth and pharynx induces vago-vagal reflexes which cause a relaxation of the gastric reservoir (Fig. -
Dynamic Colon Model (DCM): a Cine-MRI Informed Biorelevant in Vitro Model of the Human Proximal Large Intestine Characterized by Positron Imaging Techniques
pharmaceutics Article Dynamic Colon Model (DCM): A Cine-MRI Informed Biorelevant In Vitro Model of the Human Proximal Large Intestine Characterized by Positron Imaging Techniques Konstantinos Stamatopoulos 1,* , Sharad Karandikar 2, Mark Goldstein 3, Connor O’Farrell 1, Luca Marciani 4 , Sarah Sulaiman 4 , Caroline L. Hoad 5, Mark J. H. Simmons 1 and Hannah K. Batchelor 6,7 1 School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; [email protected] (C.O.); [email protected] (M.J.H.S.) 2 Department of Surgery, University Hospitals Birmingham NHS Foundation Trust, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK; [email protected] 3 Department of Radiology, University Hospitals Birmingham NHS Foundation Trust, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK; [email protected] 4 Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham NG7 2UH, UK; [email protected] (L.M.); [email protected] (S.S.) 5 Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 2QX, UK; [email protected] 6 Institute of Clinical Sciences, College of Medical and Dental Sciences, Medical School Building, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; [email protected] 7 Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK * Correspondence: [email protected] or [email protected]; Tel.: +44-0121-4145-354 Received: 8 June 2020; Accepted: 10 July 2020; Published: 13 July 2020 Abstract: This work used in vivo MRI images of human colon wall motion to inform a biorelevant Dynamic Colon Model (DCM) to understand the interplay of wall motion, volume, viscosity, fluid, and particle motion within the colon lumen. -
Motility in the Large Intestine Physiology > Digestive > Digestive
Motility in the Large Intestine Physiology > Digestive > Digestive HAUSTRAL CONTRACTIONS (Definition): Slow, segmenting movements that further mix chyme. • About every 30 minutes. • Occur in haustra: small pouches caused by the teniae coli (longitudinal smooth muscle ribbons that run along outside the entire length of the colon). Because they are shorter than the large intestine, the large intestine tucks between the teniae and form sacs • Primarily occur in ascending and transverse colons. • Produced by contractions of smooth muscle layer Steps 1. Chyme fills a haustrum 2. Distension in the haustrum. 3. Smooth muscle layer contracts 4. Contractions move chyme into the next haustrum and subsequent haustra, where the sequence begins again. #Note that haustral contractions play a relatively minor role in propelling fecal waste through the large intestine; their main function to further mix waste. Contractions also bring chyme in close contact with the large intestine mucosal layer to maximize water and electrolyte absorption • Hasutral contractions also occur in the descending and sigmoid colon to further concentrate stored fecal waste prior to elimination. MASS MOVEMENTS (Definition): slow, but powerful contractions of the large intestine that move undigested waste to the rectum for defecation via the anus. • Much like stronger and sustained peristaltic contractions. • 3-4 times a day. • Mainly in the transverse, descending, and sigmoid colons. • Produced by circular layer (smooth muscle) contractions Steps 1. Undigested waste in the transverse colon. 2. Triggered by the gastrocolic reflex (initiated following ingestion of a meal when food enters the stomach causes its distension) 3. Circular layer contracts in the transverse colon 4. Contractions move waste towards the rectum. -
Dr.Hameda Abdulmahdi College of Medicine /Dep. of Anatomy & Histology
Dr.Hameda abdulmahdi College of Medicine /Dep. of anatomy & histology 2nd stage Large Intestine The large intestine or bowel, which absorbs water and electrolytes and forms indigestible material into feces, has the following regions: the short cecum, with the ileocecal valve and the appendix; the ascending, transverse, descending, and sigmoid colon; and the rectum, where feces is stored prior to evacuation .The mucosa lacks villi and except in the rectum has no major folds. Less than one-third as long as the small intestine, the large intestine has a greater diameter (6-7 cm). The wall of the colon is puckered into a series of large sacs called haustra (L. sing. haustrum, bucket, scoop). The mucosa of the large bowel is penetrated throughout its length by tubular intestinal glands. These and the intestinal lumen are lined by goblet and absorptive cells, with a small number of enteroendocrine cells. The columnar absorptive cells or colonocytes have irregular microvilli and dilated intercellular spaces indicating active fluid absorption . Goblet cells producing lubricating mucus become more numerous along the length of the colon and in the rectum. Epithelial stem cells are located in the bottom third of each gland. The lamina propria is rich in lymphoid cells and in lymphoid nodules that frequently extend into the submucosa . The richness in MALT is related to the large bacterial population of the large intestine. The appendix has little or no absorptive function but is a significant component of MALT . The muscularis of the colon has longitudinal and circular layers but differs from that of the small intestine, with fibers of the outer layer gathered in three separate longitudinal bands called teniae coli . -
Aandp2ch25lecture.Pdf
Chapter 25 Lecture Outline See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 Introduction • Most nutrients we eat cannot be used in existing form – Must be broken down into smaller components before body can make use of them • Digestive system—acts as a disassembly line – To break down nutrients into forms that can be used by the body – To absorb them so they can be distributed to the tissues • Gastroenterology—the study of the digestive tract and the diagnosis and treatment of its disorders 25-2 General Anatomy and Digestive Processes • Expected Learning Outcomes – List the functions and major physiological processes of the digestive system. – Distinguish between mechanical and chemical digestion. – Describe the basic chemical process underlying all chemical digestion, and name the major substrates and products of this process. 25-3 General Anatomy and Digestive Processes (Continued) – List the regions of the digestive tract and the accessory organs of the digestive system. – Identify the layers of the digestive tract and describe its relationship to the peritoneum. – Describe the general neural and chemical controls over digestive function. 25-4 Digestive Function • Digestive system—organ system that processes food, extracts nutrients, and eliminates residue • Five stages of digestion – Ingestion: selective intake of food – Digestion: mechanical and chemical breakdown of food into a form usable by -
Management of the Neurogenic Bowel for Adults with Spinal Cord Injuries
Management of the Neurogenic Bowel for Adults with Spinal Cord Injuries Authors: Julie Pryor, Nursing Research & Development Leader, Royal Rehab and Clinical Associate Professor, Sydney Nursing School, The University of Sydney. Murray Fisher, Associate Professor, Sydney Nursing School, The University of Sydney, and Scholar in Residence, Royal Rehab. Dr James Middleton, Director, State Spinal Cord Injury Service, NSW Agency for Clinical Innovation. Reviewed and updated in 2013 by the authors. AGENCY FOR CLINICAL INNOVATION Level 4, Sage Building 67 Albert Avenue Chatswood NSW 2067 PO Box 699 Chatswood NSW 2057 T +61 2 9464 4666 | F +61 2 9464 4728 E [email protected] | www.aci.health.nsw.gov.au Produced by the NSW State Spinal Cord Injury Service SHPN: (ACI) 140014 ISBN: 978-1-74187-960-5 Further copies of this publication can be obtained from the Agency for Clinical Innovation website at: www.aci.health.nsw.gov.au Disclaimer: Content within this publication was accurate at the time of publication. This work is copyright. It may be reproduced in whole or part for study or training purposes subject to the inclusion of an acknowledgment of the source. It may not be reproduced for commercial usage or sale. Reproduction for purposes other than those indicated above, requires written permission from the Agency for Clinical Innovation. © Agency for Clinical Innovation 2014 Published: February 2014 HS13-130 ACKNOWLEDGEMENTS First (2002) and Second (2005) Editions: This document was originally published as a fact sheet for the Rural Spinal Cord Injury Project (RSCIP), a pilot healthcare program for people with a spinal cord injury (SCI) conducted within New South Wales involving the collaboration of Prince Henry & Prince of Wales Hospitals, Royal North Shore Hospital, Royal Rehabilitation Centre Sydney, Spinal Cord Injuries Australia and the Paraplegic & Quadriplegic Association of NSW.