Embryology of Gastrointestinal Tract( GIT)
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3 Embryology and Development
BIOL 6505 − INTRODUCTION TO FETAL MEDICINE 3. EMBRYOLOGY AND DEVELOPMENT Arlet G. Kurkchubasche, M.D. INTRODUCTION Embryology – the field of study that pertains to the developing organism/human Basic embryology –usually taught in the chronologic sequence of events. These events are the basis for understanding the congenital anomalies that we encounter in the fetus, and help explain the relationships to other organ system concerns. Below is a synopsis of some of the critical steps in embryogenesis from the anatomic rather than molecular basis. These concepts will be more intuitive and evident in conjunction with diagrams and animated sequences. This text is a synopsis of material provided in Langman’s Medical Embryology, 9th ed. First week – ovulation to fertilization to implantation Fertilization restores 1) the diploid number of chromosomes, 2) determines the chromosomal sex and 3) initiates cleavage. Cleavage of the fertilized ovum results in mitotic divisions generating blastomeres that form a 16-cell morula. The dense morula develops a central cavity and now forms the blastocyst, which restructures into 2 components. The inner cell mass forms the embryoblast and outer cell mass the trophoblast. Consequences for fetal management: Variances in cleavage, i.e. splitting of the zygote at various stages/locations - leads to monozygotic twinning with various relationships of the fetal membranes. Cleavage at later weeks will lead to conjoined twinning. Second week: the week of twos – marked by bilaminar germ disc formation. Commences with blastocyst partially embedded in endometrial stroma Trophoblast forms – 1) cytotrophoblast – mitotic cells that coalesce to form 2) syncytiotrophoblast – erodes into maternal tissues, forms lacunae which are critical to development of the uteroplacental circulation. -
Te2, Part Iii
TERMINOLOGIA EMBRYOLOGICA Second Edition International Embryological Terminology FIPAT The Federative International Programme for Anatomical Terminology A programme of the International Federation of Associations of Anatomists (IFAA) TE2, PART III Contents Caput V: Organogenesis Chapter 5: Organogenesis (continued) Systema respiratorium Respiratory system Systema urinarium Urinary system Systemata genitalia Genital systems Coeloma Coelom Glandulae endocrinae Endocrine glands Systema cardiovasculare Cardiovascular system Systema lymphoideum Lymphoid system Bibliographic Reference Citation: FIPAT. Terminologia Embryologica. 2nd ed. FIPAT.library.dal.ca. Federative International Programme for Anatomical Terminology, February 2017 Published pending approval by the General Assembly at the next Congress of IFAA (2019) Creative Commons License: The publication of Terminologia Embryologica is under a Creative Commons Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0) license The individual terms in this terminology are within the public domain. Statements about terms being part of this international standard terminology should use the above bibliographic reference to cite this terminology. The unaltered PDF files of this terminology may be freely copied and distributed by users. IFAA member societies are authorized to publish translations of this terminology. Authors of other works that might be considered derivative should write to the Chair of FIPAT for permission to publish a derivative work. Caput V: ORGANOGENESIS Chapter 5: ORGANOGENESIS -
Vocabulario De Morfoloxía, Anatomía E Citoloxía Veterinaria
Vocabulario de Morfoloxía, anatomía e citoloxía veterinaria (galego-español-inglés) Servizo de Normalización Lingüística Universidade de Santiago de Compostela COLECCIÓN VOCABULARIOS TEMÁTICOS N.º 4 SERVIZO DE NORMALIZACIÓN LINGÜÍSTICA Vocabulario de Morfoloxía, anatomía e citoloxía veterinaria (galego-español-inglés) 2008 UNIVERSIDADE DE SANTIAGO DE COMPOSTELA VOCABULARIO de morfoloxía, anatomía e citoloxía veterinaria : (galego-español- inglés) / coordinador Xusto A. Rodríguez Río, Servizo de Normalización Lingüística ; autores Matilde Lombardero Fernández ... [et al.]. – Santiago de Compostela : Universidade de Santiago de Compostela, Servizo de Publicacións e Intercambio Científico, 2008. – 369 p. ; 21 cm. – (Vocabularios temáticos ; 4). - D.L. C 2458-2008. – ISBN 978-84-9887-018-3 1.Medicina �������������������������������������������������������������������������veterinaria-Diccionarios�������������������������������������������������. 2.Galego (Lingua)-Glosarios, vocabularios, etc. políglotas. I.Lombardero Fernández, Matilde. II.Rodríguez Rio, Xusto A. coord. III. Universidade de Santiago de Compostela. Servizo de Normalización Lingüística, coord. IV.Universidade de Santiago de Compostela. Servizo de Publicacións e Intercambio Científico, ed. V.Serie. 591.4(038)=699=60=20 Coordinador Xusto A. Rodríguez Río (Área de Terminoloxía. Servizo de Normalización Lingüística. Universidade de Santiago de Compostela) Autoras/res Matilde Lombardero Fernández (doutora en Veterinaria e profesora do Departamento de Anatomía e Produción Animal. -
2/2/2011 1 Development of Development of Endodermal
2/2/2011 ZOO 401- Embryology-Dr. Salah A. Martin DEVELOPMENT OF THE DIGESTIVE SYSTEM ◦ Primitive Gut Tube ◦ Proctodeum and Stomodeum ◦ Stomach Development of Endodermal Organs ◦ Duodenum ◦ Pancreas ◦ Liver and Biliary Apparatus ◦ Spleen ◦ Midgut Wednesday, February 02, 2011 DEVELOPMENT OF THE DIGESTIVE SYSTEM 2 Wednesday, February 02, 2011 Development of Ectodermal Organs 1 ZOO 401- Embryology-Dr. Salah A. Martin ZOO 401- Embryology-Dr. Salah A. Martin Primitive Gut Tube Proctodeum and Stomodeum The primitive gut tube is derived from the dorsal part of the yolk sac , which is incorporated into the body of The proctodeum (anal pit) is the primordial the embryo during folding of the embryo during the fourth week. anus , and the stomodeum is the primordial The primitive gut tube is divided into three sections. mouth . The epithelium of and the parenchyma of In both of these areas ectoderm is in direct glands associated with the digestive tract (e.g., liver and pancreas) are derived from endoderm . contact with endoderm without intervening The muscular walls of the digestive tract (lamina mesoderm, eventually leading to degeneration propria, muscularis mucosae, submucosa, muscularis of both tissue layers. Foregut, Esophagus. externa, adventitia and/or serosa) are derived from splanchnic mesoderm . The tracheoesophageal septum divides the During the solid stage of development the endoderm foregut into the esophagus and of the gut tube proliferates until the gut is a solid tube. trachea. information. A process of recanalization restores the lumen. Wednesday, February 02, 2011 Primitive Gut Tube 3 Wednesday, February 02, 2011 Proctodeum and Stomodeum 4 ZOO 401- Embryology-Dr. Salah A. -
Embryology, Comparative Anatomy, and Congenital Malformations of the Gastrointestinal Tract
Edorium J Anat Embryo 2016;3:39–50. Danowitz et al. 39 www.edoriumjournals.com/ej/ae REVIEW ARTICLE PEER REVIEWED | OPEN ACCESS Embryology, comparative anatomy, and congenital malformations of the gastrointestinal tract Melinda Danowitz, Nikos Solounias ABSTRACT Human digestive development is an essential topic for medical students and physicians, Evolutionary biology gives context to human and many common congenital abnormalities embryonic digestive organs, and demonstrates directly relate to gastrointestinal embryology. how structural adaptations can fit changing We believe this comprehensive review of environmental requirements. Comparative gastrointestinal embryology and comparative anatomy is rarely included in the medical anatomy will facilitate a better understanding of school curriculum. However, its concepts gut development, congenital abnormalities, and facilitate a deeper comprehension of anatomy adaptations to various evolutionary ecological and development by putting the morphology conditions. into an evolutionary perspective. Features of gastrointestinal development reflect the transition Keywords: Anatomy education, Digestive, Embry- from aquatic to terrestrial environments, such as ology, Gastrointestinal tract the elongation of the colon in land vertebrates, allowing for better water reabsorption. In How to cite this article addition, fishes exhibit ciliary transport in the esophagus, which facilitates particle transport in Danowitz M, Solounias N. Embryology, comparative water, whereas land mammals develop striated anatomy, and congenital malformations of the and smooth esophageal musculature and utilize gastrointestinal tract. Edorium J Anat Embryo peristaltic muscle contractions, allowing for 2016;3:39–50. better voluntary control of swallowing. The development of an extensive vitelline drainage system to the liver, which ultimately creates Article ID: 100014A04MD2016 the adult hepatic portal system allows for the evolution of complex hepatic metabolic ********* functions seen in many vertebrates today. -
Extrinsic Factors Involved in the Differentiation of Stem Cells Into Insulin-Producing Cells: an Overview
Hindawi Publishing Corporation Experimental Diabetes Research Volume 2011, Article ID 406182, 15 pages doi:10.1155/2011/406182 Review Article Extrinsic Factors Involved in the Differentiation of Stem Cells into Insulin-Producing Cells: An Overview RebeccaS.Y.Wong Division of Human Biology, School of Medical and Health Sciences, International Medical University, No. 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur, Malaysia Correspondence should be addressed to Rebecca S. Y. Wong, rebecca [email protected] Received 16 February 2011; Accepted 28 March 2011 Academic Editor: A. Veves Copyright © 2011 Rebecca S. Y. Wong. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Diabetes mellitus is a chronic disease with many debilitating complications. Treatment of diabetes mellitus mainly revolves around conventional oral hypoglycaemic agents and insulin replacement therapy. Recently, scientists have turned their attention to the generation of insulin-producing cells (IPCs) from stem cells of various sources. To date, many types of stem cells of human and animal origins have been successfully turned into IPCs in vitro and have been shown to exert glucose-lowering effect in vivo. However, scientists are still faced with the challenge of producing a sufficient number of IPCs that can in turn produce sufficient insulin for clinical use. A careful choice of stem cells, methods, and extrinsic factors for induction may all be contributing factors to successful production of functional beta-islet like IPCs. It is also important that the mechanism of differentiation and mechanism by which IPCs correct hyperglycaemia are carefully studied before they are used in human subjects. -
Biliary Tract in Trident, an Anatomical Variation Between the Cystic Duct and Its Union to the Common Hepatic Duct
Int. J. Morphol., 37(1):308-310, 2019. Biliary Tract in Trident, an Anatomical Variation Between the Cystic Duct and its Union to the Common Hepatic Duct. A Rare Case Report Tracto Biliar en Tridente, una Variación Anatómica Entre el Conducto Cístico y su Unión al Conducto Hepático Común. Un Caso Raro Oscar Plaza1 & Freddy Moreno2 PLAZA, O. & MORENO, F. Biliary tract in trident, an anatomical variation between the cystic duct and its union to the common hepatic duct. A rare case report. Int. J. Morphol. 37(1):308-310, 2019. SUMMARY: Given that the gallbladder and the biliary tract are subject to multiple anatomical variants, detailed knowledge of embryology and its anatomical variants is essential for the recognition of the surgical field when the gallbladder is removed laparoscopically or by laparotomy, even when radiology procedures are performed. During a necropsy procedure, when performing the dissection of the bile duct is a rare anatomical variant of the bile duct, in this case the cystic duct joins at the confluence of the right and left hepatic ducts giving an appearance of trident. This rare anatomical variant in the formation of common bile duct is found during the exploration of the bile duct during a necropsy procedure, it is clear that the wrong ligation of a common hepatic duct can cause a great morbi-mortality in the post- surgical of biliary surgery. This rare anatomical variant not previously described is put in consideration to the scientific community. Anatomical variants of the biliary tract are associated with high rates of morbidity and mortality, causing serious bile duct injuries. -
The Missing Link CASE REPORT
CASE REPORT 531 The missing link J. Maus1, S. Naegels1, H. Slabbynck2, L. De Waele1, I. Ruytjens1 (1) ZNA Middelheim, Department of Gastro-enterology ; (2) ZNA Middelheim, Department of Pneumology. Abstract We present a case of a 28-year old woman who presented with bizarre wheezing breath sounds on expiration and dysphagia, with unexplained significant dilation of the esophagus mimicking achalasia finally leading to the diagnosis of a very small congenital tracheoesophageal fistula (TEF). Congenital TEF is usually detected shortly after birth and is typically accompanied by esophageal atresia. Congenital TEF without esophageal atresia (H-type fistula) can be missed in early life and diagnosis may be postponed until adulthood due to subtle symptoms. Diagnosis is usually based upon a combination of esophagoscopy, bronchoscopy, barium esophagography and CT-scan. The only clue can be the finding of a significant dilated aperistaltic esophagus, with subsequent more detailed CT reconstruction revealing a very tiny H-type TEF. It is important to raise the awareness of small H-type TEF as a possible cause of achalasia-like esophageal dilation in adulthood and of very unusual and bizarre wheezing breath sounds. (Acta gastroenterol. belg., 2018, 81, 531-533). Key words : adult ; congenital ; tracheoesophageal fistula ; H-type. Introduction Most patients with congenital TEF are diagnosed shortly after birth or in early life due to frequent association with esophageal atresia which leads to life-threatening complications and warrants immediate surgery. (1) H-type TEF, where esophageal atresia is absent, is rare and diagnosis may be postponed until adulthood due to subtle symptoms and physician unfamiliarity (2). -
The Urogenital Sinus 1.The Anal Membrane Deepens to Form the Proctodeum
Duodenum -The duodenum develops from the caudal part of the foregut and cranial part of the midgut . So, it is supplied by branches from both celiac and cranial mesenteric arteries. -Due to rotation of the stomach, the duodenum rotates to be located in the right side. Anomalies of duodenum: 1-Duodenal stenosis:- Narrowing of the duodenal lumen results from:- a-Incomplete recanalization of duodenum b-It may be caused by pressure from an annular pancreas. 2-Duodenal atresia:- -A short segment of duodenum is occluded due to failure of recanalization of this segment. -In fetus with duodenal atresia , vomiting begins within few hours of birth before ingestion of any fluid -Often there is distension of epigastrium resulting from overfilled stomach and upper duodenum. Liver -The liver appears as a hepatic bud from the ventral aspect of (duodenum) distal end of the foregut. -The hepatic bud is divided into two cranial and caudal. -The cranial part gives liver and hepatic duct while caudal part gives gall bladder and cystic duct. -The hepatic bud directed towards the septum transversum. - The hepatic bud differentiate into hepatic cords which invade the umbilical and vitelline veins of the septum transversum and transforms them into hepatic sinusoids. - The hepatic cords differentiate into the parenchyma and the lining of the bile duct. - The hemopiotic cells , capsule and connective tissue supporting the liver are differentiated from the mesoderm of the septum transversum. Anomalies of liver:- 1-Atresia of gall bladder This results from failure of vacuolization of the gall bladder, consequently the bladder remains atretic i.e solid. -
BGD B Lecture Notes Docx
BGD B Lecture notes Lecture 1: GIT Development Mark Hill Trilaminar contributions • Overview: o A simple tube is converted into a complex muscular, glandular and duct network that is associated with many organs • Contributions: o Endoderm – epithelium of the tract, glands, organs such as the liver/pancreas/lungs o Mesoderm (splanchnic) – muscular wall, connective tissue o Ectoderm (neural crest – muscular wall neural plexus Gastrulation • Process of cell migration from the epiblast through the primitive streak o Primitive streak forms on the bilaminar disk o Primitive streak contains the primitive groove, the primitive pit and the primitive node o Primitive streak defines the body axis, the rostral caudal ends, and left and right sides Thus forms the trilaminar embryo – ectoderm, mesoderm, endoderm • Germ cell layers: o ectoderm – forms the nervous system and the epidermis epithelia 2 main parts • midline neural plate – columnar epithelium • lateral surface ectoderm – cuboidal, containing sensory placodes and skin/hair/glands/enamel/anterior pituitary epidermis o mesoderm – forms the muscle, skeleton, and connective tissue cells migrate second migrate laterally, caudally, rostrally until week 4 o endoderm – forms the gastrointestinal tract epithelia, the respiratory tract and the endocrine system cells migrate first and overtake the hypoblast layer line the primary yolk sac to form the secondary yolk sac • Membranes: o Rostrocaudal axis Ectoderm and endoderm form ends of the gut tube, no mesoderm At each end, form the buccopharyngeal -
GI Embryology 2 the Foregut
GI embryology 2 The Foregut • At first the esophagus is short • but with descent of the heart and lungs it lengthens rapidly • The muscular coat, which is formed by surrounding splanchnic mesenchyme, is striated in its upper two-thirds and innervated by the vagus; • the muscle coat is smooth in the lower third and is innervated by the splanchnic plexus. Esophageal Abnormalities • Esophageal atresia and/or tracheoesophageal fistula results either from spontaneous posterior deviation of the tracheoesophageal septum or from some mechanical factor pushing the dorsal wall of the foregut anteriorly • In its most common form the proximal part of the esophagus ends as a blind sac, and the distal part is connected to the trachea by a narrow canal just above the bifurcation • Other types of defects in this region occur much less frequently • Atresia of the esophagus prevents normal passage of amniotic fluid into the intestinal tract, resulting in accumulation of excess fluid in the amniotic sac (polyhydramnios). • In addition to atresias, the lumen of the esophagus may narrow, producing esophageal stenosis, usually in the lower third • Stenosis may be caused by incomplete recanalization, vascular abnormalities, or accidents that compromise blood flow • Occasionally the esophagus fails to lengthen sufficiently and the stomach is pulled up into the esophageal hiatus through the diaphragm. • The result is a congenital hiatal hernia Development of the glands • Most glands are formed during development by proliferation of epithelial cells so that they project into the underlying connective tissue • Some glands retain their continuity with the surface via a duct and are known as EXOCRINE GLANDS, as they maintain contact with the surface • Other glands lose this direct continuity with the surface when their ducts degenerate during development. -
Gastroesophageal Reflux: Anatomy and Physiology
26th Annual Scientific Conference | May 1-4, 2017 | Hollywood, FL Gastroesophageal Reflux: Anatomy and Physiology Amy Lowery Carroll, MSN, RN, CPNP- AC, CPEN Children’s of Mississippi at The University of Mississippi Medical Center Jackson, Mississippi Disclosure Information I have no disclosures. Objectives • Review embryologic development of GI system • Review normal anatomy and physiology of esophagus and stomach • Review pathophysiology of Gastroesophageal Reflux 1 26th Annual Scientific Conference | May 1-4, 2017 | Hollywood, FL Embryology of the Gastrointestinal System GI and Respiratory systems are derived from the endoderm after cephalocaudal and lateral folding of the yolk sack of the embryo Primitive gut can be divided into 3 sections: Foregut Extends from oropharynx to the liver outgrowth Thyroid, esophagus, respiratory epithelium, stomach liver, biliary tree, pancreas, and proximal portion of duodenum Midgut Liver outgrowth to the transverse colon Develops into the small intestine and proximal colon Hindgut Extends from transverse colon to the cloacal membrane and forms the remainder of the colon and rectum Forms the urogenital tract Embryology of the Gastrointestinal System Respiratory epithelium appears as a bud of the esophagus around 4th week of gestation Tracheoesophageal septum develops to separate the foregut into ventral tracheal epithelium and dorsal esophageal epithelium Esophagus starts out short and lengthens to final extent by 7 weeks Anatomy and Physiology of GI System Upper GI Tract Mouth Pharynx Esophagus Stomach