DOCSLIB.ORG

Bmps on the Road to Hepatogenesis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Bmps on the Road to Hepatogenesis Downloaded from genesdev.cshlp.org on October 2, 2021 - Published by Cold Spring Harbor Laboratory Press PERSPECTIVE BMPs on the road to hepatogenesis Stephen A. Duncan1 and Alistair J. Watt Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA onset of hepatic development. However, the time-hon- Classical transplantation studies using chick and quail ored belief that hepatic induction is solely a matter of embryos demonstrated that the vertebrate liver paren- the heart has now been overturned by further work from chyma is derived from an outgrowth of the ventral fore- the Zaret lab (Rossi et al. 2001, this issue), showing that gut endoderm, referred to as the liver bud (LeDouarin bone morphogenic proteins (BMPs) secreted from sep- 1964, 1968, 1975). This process, illustrated in Figure 1, tum transversum mesenchyme are needed in concert initiates at around gestation day 8.25 (7–8 somites) in the with cardiac-derived FGFs to induce the ventral endo- mouse (Gualdi et al. 1996). Invagination of the foregut derm to adopt a hepatic fate. positions a ventral portion of foregut endoderm next to The septum transversum mesenchyme remains the developing cardiac mesoderm. Early on, it was pro- closely associated with the liver throughout develop- posed that specification of the hepatic diverticulum re- ment and ultimately contributes toward the diaphragm lied upon the close proximity of cardiac mesoderm. Sev- and epicardium. Following specification of the hepatic eral studies, the most recent by Gualdi et al. (1996), pro- lineage, hepatoblasts rapidly proliferate and migrate vided strong evidence to support this proposal. In away from the foregut into the adjacent septum trans- general, it was found that ventral endoderm from either versum mesenchyme (Fig. 1). Using chick/quail grafts mouse or chick was unable to adopt a hepatic fate, or and coculture experiments with mouse tissues, it was express characteristic hepatic mRNAs, if it were grown found that hepatoblasts require an undefined signal from in the absence of developing cardiac tissue (LeDouarin the septum transversum mesenchyme to complete their 1975; Houssaint 1980; Fukuda-Taira 1981; Gualdi et al. differentiation into mature hepatocytes (LeDouarin 1996). Moreover, this inductive capacity seemed to be 1968; Houssaint 1980). However, this signal to differen- restricted to cardiac mesoderm, because other noncar- tiate was not restricted to the septum transversum, be- diac mesoderms failed to induce hepatic development cause hepatic differentiation could also be induced by (Fukuda 1979; Fukuda-Taira 1981). culturing hepatic endoderm with heterologous mesen- chymes (Houssaint 1980). The possibility that septum Not so lonely heart transversum mesenchyme could also contribute toward the distinct act of specifying the hepatic lineage had not Although it was firmly established that the developing previously been considered, because it was believed that heart played an important inductive role during hepato- only cardiac tissue was required. However, Rossi et al. genesis, the molecular mechanisms underlying this ac- (2001) have now addressed this possibility by taking ad- tivity were defined only recently, largely through work vantage of a transgenic mouse in which expression of a carried out by the Zaret laboratory (Gualdi et al. 1996; LacZ reporter gene is controlled by the endogenous Jung et al. 1999). Jung et al. (1999) used a tissue explant Bmp4 transcriptional regulatory elements (Lawson et al. assay to demonstrate that fibroblast growth factors 1999). The LacZ expression pattern in this mouse mim- (FGFs) 1 or 2 could substitute for cardiac mesoderm in icked that of endogenous BMP4, including expression in inducing ventral endoderm to elicit a hepatogenic re- the septum transversum but not in the ventral foregut albumin sponse. In these experiments expression of endoderm. Importantly, the authors identified LacZ ex- mRNA, a marker of nascent hepatic cells, could be de- pressing septum transversum mesenchyme that closely tected within ventral endoderm that had been isolated apposed the ventral endoderm around the time of hepatic from embryos prior to specification of the liver (2–6 specification (8 somites). This implied, through guilt by somites) and cultured for 2 d either in the presence of association, that the septum transversum might act in a cardiac tissue or in the presence of FGF1 or FGF2. In juxtacrine fashion to influence hepatic specification. contrast, when prehepatic ventral endoderm was cul- Moreover, the fact that BMP4 was expressed in the sep- albumin tured alone it failed to express mRNA. These tum transversum raised the possibility that BMPs could data strongly supported a model wherein FGFs secreted mediate the proposed inductive action. from the developing heart were sufficient to induce the 1Corresponding author. BMPs and FGFs act in concert E-MAIL [email protected]; FAX (414) 456-6517. Article and publication are at http://www.genesdev.org/cgi/doi/10.1101/ An essential role for BMP signaling was demonstrated gad.920601. directly by culturing the prehepatic ventral endoderm GENES & DEVELOPMENT 15:1879–1884 © 2001 by Cold Spring Harbor Laboratory Press ISSN 0890-9369/01 $5.00; www.genesdev.org 1879 Downloaded from genesdev.cshlp.org on October 2, 2021 - Published by Cold Spring Harbor Laboratory Press Duncan and Watt Figure 1. FGFs and BMPs in liver devel- opment. Sagittal sections through em- bryos at 8.25 d postcoitum (dpc) (upper left) and 9.5 dpc (lower left), with each area undergoing hepatogenesis boxed and shown in detail on the right. By this stage (2–6somite stage), invagination of the foregut endoderm positions a portion of ventral endoderm (green) adjacent to the cardiac mesoderm (red) and the septum transversum mesenchyme (blue). At this stage, the entire endoderm expresses the transcription factor Hnf3, making the en- doderm competent to adopt a hepatic fate. BMP signaling from the septum transver- sum and FGF signaling from the cardiac mesoderm induce a portion of the ventral endoderm to initiate hepatogenesis (green), leaving the distal lip of endoderm to form the ventral pancreas (yellow). This results in the expression of transcription factors such as Hex and Gata4 necessary for subsequent developmental stages. By 8.5 dpc the hepatic endoderm thickens to form the liver bud. The continued action of BMPs and FGFs is required for the pro- liferation and outgrowth of the liver bud. By 9.5 dpc Hnf4␣, which is necessary to complete hepatocyte differentiation, is ex- pressed in the migrating hepatic cells. with cardiac and septum transversum tissue in the pres- This model is appealing on a number of levels. The ence of the Xenopus laevis noggin protein (Xnoggin). fact that two tissues must contribute signals that induce Xnoggin acts as a potent antagonist of BMP action, and hepatogenesis reinforces the dynamic, multidimensional its presence in the media of cultured explants was found nature of embryogenesis. It means, simply, that a tissue to inhibit the onset of albumin mRNA expression that is competent to follow a given fate must be posi- within the ventral endoderm relative to control cultures tioned in the right place at the right time to fulfill that lacking Xnoggin. The demonstration that BMPs were fate. In this regard, the identification of FGF and BMPs as necessary for hepatic specification raised the question of inducers of hepatic development define a mechanism why, in previous experiments, FGF alone was capable of whereby outgrowth of the liver is positioned along the inducing albumin mRNA expression in cultured ventral anterior–posterior of the ventral foregut. In addition to endoderm. The authors suggest that it is likely, in retro- deciding the position of liver development, it is likely spect, that the ventral endoderm isolates contained that the combined action of FGF and BMP signaling de- BMP-expressing septum transversum mesenchyme. In- fines the domain of endoderm that gives rise to the ven- deed, examination of cultured endoderm explants re- tral pancreas. Like the liver, ventral pancreas also origi- vealed mesenchymal cells that expressed the septum nates as a budding outgrowth of the ventral endoderm. transversum marker Mrg1 as well as BMP4. The authors Deutsch et al. (2001) recently demonstrated, again using also found that Xnoggin inhibited FGF-induced expres- explant cultures, that the liver and ventral pancreatic sion of albumin mRNA in cultured ventral endoderm. domains are nonoverlapping, that is, the ventral pan- This result was illuminating because it also demon- creas derives from a lip of endoderm that extends beyond strated that FGF alone was insufficient to induce the the immediate vicinity of the developing heart (Fig. 1). onset of a hepatic gene expression program within the Further experiments showed that the entire ventral en- ventral endoderm. Similarly, explants cultured in the doderm, including the portion fated to become liver, is presence of exogenous BMPs but in the absence of car- innately capable of adopting a pancreatic fate by default. diac tissue or FGF also failed to express albumin mRNA. Indeed, when ventral endoderm that would normally fol- These results prompt a model in which at least two sig- low a hepatic fate is cultured in the absence of cardiac naling pathways originating from different tissue mesoderm or FGF, it initiates a gene expression program sources, FGF (cardiac mesoderm) and BMP (septum that is characteristic of the
Load more

Recommended publications
  • 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
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • A Morphological Study of the Development of the Human Liver I
    A Morphological Study of the Development of the Human Liver I. DEVELOPMENT OF THE HEPATIC DIVERTICULUM ’ CHARLES B. SEVERN2 Department of Anatomy, University of Michigan, Ann Arbor, Michigan ABSTRACT The development of the hepatic diverticulum was examined in 38 human embryos representing somite stages 1, 5, 8 and 10 through 29, inclu- sive. Interpretations were based on light microscopic study of serial sections of these embryos. The liver primordium was first identified in a five-somite embryo as a flat plate of endodermal cells continuous with, but lying ventral to, the endoderm of the foregut at the anterior intestinal portal. It is positioned caudal and ventral to the developing heart. This plate of endoderm subsequently undergoes a progres- sive folding due to differential growth of adjacent structures. During the folding process there is a close spatial relationship between the cells of the endodermal plate and the caudal and ventral endothelial lining of the atrium and the sinus venosus. The result of this folding is the establishment of a “T-shaped” diver- ticulum which projects ventrally and cephalically from the gut tract. The hepatic diverticulum is established by the 20 somite-stage embryo. This mode of develop- ment of the hepatic diverticulum is compared to the classical interpretation and to the development of other visceral organs. The lack of an extensive sequential of the intrahepatic duct system, correla- series of human embryonic material has tion of the liver’s developmental pattern prevented past investigators from obtain- with its definitive architectural pattern, ing anything more than general and rather and comparison of the origin and develop- vague concepts as to how the human liver ment of the liver in various species of verte- develops.
    [Show full text]
  • Flexion and Neural Tube Formation
    Flexion and Neural Tube Formation RECOMMENDED READING: Larsen: Human Embryology 3rd edition 1. Review figures 2.4-2.6 and such text as necessary (pp 41-43 for source of definitive yolk sac and extra-embryonic coelom (cavity). 2. Pp 131-143. Text covers the formation of the intra-embryonic coelom and its division into peritoneal, pleural and pericardial cavities plus closure of the diaphragm. 3. Pp 57, Figure 3-4; pp 85-93. Text covers the transformation of the neural plate into the neural tube, the initial phases of differentiation of this tube and the origin of the neural crest. The multiple fates of neural crest derivatives will be given in other lectures. LEARNING OBJECTIVES: 1.Review information on the formation of the extra-embryonic coelom from prior lecture. Embryonic flexion and folding 2. Understand how the lateral plate mesoderm divides into somatopleure and splanchnopleure, which flex (fold) in the lateral plane and fuse ventrally. This results in the enclosure of some of the extra-embryonic coelom into the embryo. 3. Note that head/tail flexion is "driven" in part by rapid growth of the CNS and relative stiffness of notochord. 4. Understand the "accomplishments" of flexion and folding: a. Segregation of embryonic from extra-embryonic tissues except at umbilical cord. b. Enclosure the intra-embryonic coelom. c. Narrowing of the gut tube. d. Postioning of the buccopharyngeal membrane (future mouth) and cloacal membrane (future opening of urinary and gastrointestinal tracts) to a ventral position. e. "Movement" of the septum transversum and cardiogenic tissues ventrally. Formation of and closure of the neural tube, division into primary brain vesicles and origin of neural crest.
    [Show full text]
  • Gastrointestinal Block DEVELOPMENT of PANCREAS & SMALL INTESTINE ﯾﻌﺘﺒﺮ اﻟﻌﻤﻞ ﻣﺼﺪر ﻟﻠﻤﺬاﻛﺮة واﻟﻤﺮاﺟﻌﺔ ______
    Gastrointestinal block DEVELOPMENT OF PANCREAS & SMALL INTESTINE ﯾﻌﺘﺒﺮ اﻟﻌﻤﻞ ﻣﺼﺪر ﻟﻠﻤﺬاﻛﺮة واﻟﻤﺮاﺟﻌﺔ ____________________________________________________________________________________________________________ Objectives ★ Describe the development of the duodenum. ★ Describe the development of the pancreas. ★ Describe the development of the small intestine. ★ Identify the congenital anomalies of the small intestine : ● Congenital omphalocele. ● Umbilical hernia. ● Meckel’s diverticulum. Resources ★ 435 embryology (males & females) lectures. ★ BRS embryology Book. ★ Langman embryology book. Color Index ★ IMPORTANT ★ Day, Week, Month ★ Doctor notes and extra information. Team Leaders Afnan AlMalki & Helmi M AlSwerki. ❖ INTRODUCTION the Extra information for better understanding ​ ​( ​ ​ ) : ​Overview ★ The primitive gut tube is formed from the incorporation of the dorsal part of the yolk sac into the embryo due to the craniocaudal folding and lateral folding of the embryo. ★ The ​primitive gut tube​ extends from the oropharyngeal membrane to the cloacal membrane and is ​divided​ into the ​foregut​, ​midgut​,​and​ ​hindgut​. ★ Arterial supply: ○ Foregut​ derivatives are supplied by the ​celiac trunk​.The exception to this is the esophagus( not all of the esophagus ). ○ Derivatives of the ​midgut ​ are supplied by the ​superior mesenteric artery. ○ Derivatives of the ​hindgut​ are supplied by the inferior mesenteric artery. ★ Stages in the development of duodenum, liver, biliary ducts and pancreas ​(pic.A-D). ★ pic A > ​4th week​ , pic B and C >​ 5th week​ , pic D > ​6th week ★ Early in the​ ​4th week​ , the duodenum develops from the endoderm of primordial gut of : ​Caudal part of foregut , Cranial part of midgut & Splanchnic mesoderm. ★ The junction of the 2 parts of the gut lies just below or distal to the origin of bile duct ​(pic. C&D). ★ Midgut ( development of small intestine ) : Derivatives of ​cranial ​part of the Derivatives of the ​caudal ​part of ​midgut Derivative of the ​caudal​ ​part midgut ​loop.
    [Show full text]
  • Article Download
    wjpmr, 2020,6(11), 183-187 SJIF Impact Factor: 5.922 WORLD JOURNAL OF PHARMACEUTICAL Research Article Manoj et al. World Journal of Pharmaceutical and Medical Research AND MEDICAL RESEARCH ISSN 2455-3301 www.wjpmr.com Wjpmr AN INSIGHT INTO THE ORGANOGENESIS OF HUMAN LIVER *A. Manoj and Annamma Paul Department of Anatomy, School of Medical Education, M.G University (Accredited by NAAC with A-Grade), Kottayam, Kerala, India. *Corresponding Author: A. Manoj Department of Anatomy, Government Medical College, Thrissur- 680596, under Directorate of Medical Education of Health and Family Welfare –Government of Kerala, India. Article Received on 02/09/2020 Article Revised on 23/09/2020 Article Accepted on 13/10/2020 ABSTRACT The objective of the current study was to learn the development of liver inorder to strengthen the Gross Anatomy and Microsopic Anatomy studies of liver and also ascertain the congenital anomalies of liver due to disturbance in its organogenesis. Hepatogenesis commence at Fourth week of Intrauterine life by proliferation of endodermal diverticulam at the ventral aspect of the junction between Foregut and mid gut into the septum transversum where it divides into Pars Hepatica and Pars Cystica forms liver and gall bladder respectively. On seventh week of fetal development Pars hepatica differentiates into clusters of liver parenchyma in which billiary capillaries emerges for delivery of its secretions. The trunk of hepatic buds persists as common bile duct and its two branches were right and left hepatic ducts. Haemopoeitic cells, Kuffer cells, Capsule and fibroareolar tissue derived from mesoderm of septum transversum. Fibroblast Growth Factor 2 (FGF2) secreted by cardiac mesoderm induces the development of hepatic bud which generates hepatoblasts, intending the formation of hepatocytes.
    [Show full text]
  • High-Yield Embryology 4
    LWBK356-FM_pi-xii.qxd 7/14/09 2:03 AM Page i Aptara Inc High-Yield TM Embryology FOURTH EDITION LWBK356-FM_pi-xii.qxd 7/14/09 2:03 AM Page ii Aptara Inc LWBK356-FM_pi-xii.qxd 7/14/09 2:03 AM Page iii Aptara Inc High-Yield TM Embryology FOURTH EDITION Ronald W. Dudek, PhD Professor Brody School of Medicine East Carolina University Department of Anatomy and Cell Biology Greenville, North Carolina LWBK356-FM_pi-xii.qxd 7/14/09 2:03 AM Page iv Aptara Inc Acquisitions Editor: Crystal Taylor Product Manager: Sirkka E. Howes Marketing Manager: Jennifer Kuklinski Vendor Manager: Bridgett Dougherty Manufacturing Manager: Margie Orzech Design Coordinator: Terry Mallon Compositor: Aptara, Inc. Copyright © 2010, 2007, 2001, 1996 Lippincott Williams & Wilkins, a Wolters Kluwer business. 351 West Camden Street 530 Walnut Street Baltimore, MD 21201 Philadelphia, PA 19106 Printed in China All rights reserved. This book is protected by copyright. No part of this book may be reproduced or transmitted in any form or by any means, including as photocopies or scanned-in or other electronic copies, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews. Materials appear- ing in this book prepared by individuals as part of their official duties as U.S. government employees are not covered by the above-mentioned copyright. To request permission, please contact Lippincott Williams & Wilkins at 530 Walnut Street, Philadelphia, PA 19106, via email at [email protected], or via website at lww.com (products and services).
    [Show full text]
  • 26 April 2010 TE Prepublication Page 1 Nomina Generalia General Terms
    26 April 2010 TE PrePublication Page 1 Nomina generalia General terms E1.0.0.0.0.0.1 Modus reproductionis Reproductive mode E1.0.0.0.0.0.2 Reproductio sexualis Sexual reproduction E1.0.0.0.0.0.3 Viviparitas Viviparity E1.0.0.0.0.0.4 Heterogamia Heterogamy E1.0.0.0.0.0.5 Endogamia Endogamy E1.0.0.0.0.0.6 Sequentia reproductionis Reproductive sequence E1.0.0.0.0.0.7 Ovulatio Ovulation E1.0.0.0.0.0.8 Erectio Erection E1.0.0.0.0.0.9 Coitus Coitus; Sexual intercourse E1.0.0.0.0.0.10 Ejaculatio1 Ejaculation E1.0.0.0.0.0.11 Emissio Emission E1.0.0.0.0.0.12 Ejaculatio vera Ejaculation proper E1.0.0.0.0.0.13 Semen Semen; Ejaculate E1.0.0.0.0.0.14 Inseminatio Insemination E1.0.0.0.0.0.15 Fertilisatio Fertilization E1.0.0.0.0.0.16 Fecundatio Fecundation; Impregnation E1.0.0.0.0.0.17 Superfecundatio Superfecundation E1.0.0.0.0.0.18 Superimpregnatio Superimpregnation E1.0.0.0.0.0.19 Superfetatio Superfetation E1.0.0.0.0.0.20 Ontogenesis Ontogeny E1.0.0.0.0.0.21 Ontogenesis praenatalis Prenatal ontogeny E1.0.0.0.0.0.22 Tempus praenatale; Tempus gestationis Prenatal period; Gestation period E1.0.0.0.0.0.23 Vita praenatalis Prenatal life E1.0.0.0.0.0.24 Vita intrauterina Intra-uterine life E1.0.0.0.0.0.25 Embryogenesis2 Embryogenesis; Embryogeny E1.0.0.0.0.0.26 Fetogenesis3 Fetogenesis E1.0.0.0.0.0.27 Tempus natale Birth period E1.0.0.0.0.0.28 Ontogenesis postnatalis Postnatal ontogeny E1.0.0.0.0.0.29 Vita postnatalis Postnatal life E1.0.1.0.0.0.1 Mensurae embryonicae et fetales4 Embryonic and fetal measurements E1.0.1.0.0.0.2 Aetas a fecundatione5 Fertilization
    [Show full text]
  • Cholelithiasis in an Intrahepatic Gallbladder
    International Surgery Journal Chandrasekar G et al. Int Surg J. 2017 Sep;4(9):3177-3179 http://www.ijsurgery.com pISSN 2349-3305 | eISSN 2349-2902 DOI: http://dx.doi.org/10.18203/2349-2902.isj20173912 Case Report Cholelithiasis in an intrahepatic gallbladder Chandrasekar G.*, Vivek Nagappa Department of General Surgery, Government Stanley Medical College and Hospital, Chennai, Tamil Nadu, India Received: 19 June 2017 Accepted: 22 July 2017 *Correspondence: Dr. Chandrasekar G., E-mail: [email protected] Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Intrahepatic gall bladder (GB) is an uncommonly encountered condition in clinical practice characterized by ectopic location of GB within the hepatic parenchyma. This condition not only produces difficulty in clinical diagnosis of various GB diseases especially cholecystitis and carcinoma but also in their management including cholecystectomy. An ectopic partial intrahepatic GB can make cholecystectomy hazardous, when indicated. A case of cholelithiasis in an intrahepatic gallbladder with concurrent choledocholithiasis is reported. The patient initially presented with pain over the right upper abdomen. The diagnosis was made during intraoperative laparoscopic cholecystectomy. This article discusses about difficultly faced during cholecystectomy and rarity of the presentation. Keywords: Cholelithiasis in ectopic gall bladder, Hepatic cyst like gall bladder, Intrahepatic gall bladder, Laparoscopic removal of intrahepatic gall bladder INTRODUCTION Anatomy An intrahepatic gallbladder is one that is partially or The gallbladder is a piriform (pear-shaped) organ that lies completely embedded within the liver parenchyma.
    [Show full text]