Unit 3 Embryo Questions
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
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 -
Notch Signaling Regulates the Differentiation of Neural Crest From
ß 2014. Published by The Company of Biologists Ltd | Journal of Cell Science (2014) 127, 2083–2094 doi:10.1242/jcs.145755 RESEARCH ARTICLE Notch signaling regulates the differentiation of neural crest from human pluripotent stem cells Parinya Noisa1,2, Carina Lund2, Kartiek Kanduri3, Riikka Lund3, Harri La¨hdesma¨ki3, Riitta Lahesmaa3, Karolina Lundin2, Hataiwan Chokechuwattanalert2, Timo Otonkoski4,5, Timo Tuuri5,6,* and Taneli Raivio2,4,*,` ABSTRACT Kokta et al., 2013). Neural crest cells originate from neuroectoderm at the border between the neural plate and the Neural crest cells are specified at the border between the neural epiderm (Meulemans and Bronner-Fraser, 2004), and they are plate and the epiderm. They are capable of differentiating into marked by the expression of genes that are specific for the neural- various somatic cell types, including craniofacial and peripheral plate border, such as DLX5, MSX1, MSX2 and ZIC1. Later, during nerve tissues. Notch signaling plays important roles during the neural-tube folding process, neural crest cells remain within neurogenesis; however, its function during human neural crest the neural folds and subsequently localize inside the dorsal development is poorly understood. Here, we generated self- portion of the neural tube. These premigratory neural crest cells renewing premigratory neural-crest-like cells (pNCCs) from human express specifier genes, such as SNAIL (also known as SNAI1), pluripotent stem cells (hPSCs) and investigated the roles of Notch SLUG (also known as SNAI2), SOX10 and TWIST1 (LaBonne and signaling during neural crest differentiation. pNCCs expressed Bronner-Fraser, 2000; Mancilla and Mayor, 1996). Following the various neural-crest-specifier genes, including SLUG (also known formation of the neural tube, premigratory neural crest cells as SNAI2), SOX10 and TWIST1, and were able to differentiate into undergo an epithelial-to-mesenchymal transition (EMT) and most neural crest derivatives. -
The Migration of Neural Crest Cells and the Growth of Motor Axons Through the Rostral Half of the Chick Somite
/. Embryol. exp. Morph. 90, 437-455 (1985) 437 Printed in Great Britain © The Company of Biologists Limited 1985 The migration of neural crest cells and the growth of motor axons through the rostral half of the chick somite M. RICKMANN, J. W. FAWCETT The Salk Institute and The Clayton Foundation for Research, California division, P.O. Box 85800, San Diego, CA 92138, U.S.A. AND R. J. KEYNES Department of Anatomy, University of Cambridge, Downing St, Cambridge, CB2 3DY, U.K. SUMMARY We have studied the pathway of migration of neural crest cells through the somites of the developing chick embryo, using the monoclonal antibodies NC-1 and HNK-1 to stain them. Crest cells, as they migrate ventrally from the dorsal aspect of the neural tube, pass through the lateral part of the sclerotome, but only through that part of the sclerotome which lies in the rostral half of each somite. This migration pathway is almost identical to the path which pre- sumptive motor axons take when they grow out from the neural tube shortly after the onset of neural crest migration. In order to see whether the ventral root axons are guided along this pathway by neural crest cells, we surgically excised the neural crest from a series of embryos, and examined the pattern of axon outgrowth approximately 24 h later. In somites which contained no neural crest cells, ventral root axons were still found only in the rostral half of the somite, although axonal growth was slightly delayed. These axons were surrounded by sheath cells, which had presumably migrated out of the neural tube, to a point about 50 jan proximal to the growth cones. -
Development of the Female Reproductive System
Development of the female Reproductive System Dr. Susheela Rani Genital System •Gonads •Internal genitals •External genitals Determining sex – chronology of events •Determined Genetic sex at fertilization Gonadal sex •6th week Phenotypic sex •Differentiation of Behavioural Psyche - Preoptic and Median region Sex of Hypothalamus Genetic Sex Genetic sex of an embryo is determined at the time of fertilization, depending on whether the spermatocyte carries an X or a Y chromosome. The ‘Master’ Gene that determines Gender • SRY (Sex determining Region Y gene) • Has a testis-determining effect on the indifferent gonads. • Small gene (a single exon) • Localized on the shorter arm of the Y chromosome (Yp) • Gets expressed in the gonadal cells • Controls a whole number of further genes on the autosomes as well as on the X chromosome. • Causes development of Testes • Pseudo autosomal regions PAR1 and PAR 2 – Yellow • Heterochromatin – redundant DNA sequences – Pink • SRY – Region for Sex Determining Gene- Dark red • ZFY , Y linked Zinc Finger Protein – Orange • Spermatogenesis Genes in long arm – Azoospermia factor AZF • Telomeres – green • Centromeres - Blue It is not the number of gonosomes that is decisive for the gender, but rather the presence or absence of the Y-chromosome Aneuploidy and Euploidy of Gonosomes Karyotype Phenotypic Gonad Syndrome Fate Gender 45, XO Female Ovaries Turner’s Atrophy of Ovaries in the fetus 45, YO ------ ----- ----- Absence of X chromosome is lethal 46, XX Female Ovaries Normal Normal Development Woman 47, XXX Female -
Pluripotency Factors Regulate Definitive Endoderm Specification Through Eomesodermin
Downloaded from genesdev.cshlp.org on September 23, 2021 - Published by Cold Spring Harbor Laboratory Press Pluripotency factors regulate definitive endoderm specification through eomesodermin Adrian Kee Keong Teo,1,2 Sebastian J. Arnold,3 Matthew W.B. Trotter,1 Stephanie Brown,1 Lay Teng Ang,1 Zhenzhi Chng,1,2 Elizabeth J. Robertson,4 N. Ray Dunn,2,5 and Ludovic Vallier1,5,6 1Laboratory for Regenerative Medicine, University of Cambridge, Cambridge CB2 0SZ, United Kingdom; 2Institute of Medical Biology, A*STAR (Agency for Science, Technology, and Research), Singapore 138648; 3Renal Department, Centre for Clinical Research, University Medical Centre, 79106 Freiburg, Germany; 4Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom Understanding the molecular mechanisms controlling early cell fate decisions in mammals is a major objective toward the development of robust methods for the differentiation of human pluripotent stem cells into clinically relevant cell types. Here, we used human embryonic stem cells and mouse epiblast stem cells to study specification of definitive endoderm in vitro. Using a combination of whole-genome expression and chromatin immunoprecipitation (ChIP) deep sequencing (ChIP-seq) analyses, we established an hierarchy of transcription factors regulating endoderm specification. Importantly, the pluripotency factors NANOG, OCT4, and SOX2 have an essential function in this network by actively directing differentiation. Indeed, these transcription factors control the expression of EOMESODERMIN (EOMES), which marks the onset of endoderm specification. In turn, EOMES interacts with SMAD2/3 to initiate the transcriptional network governing endoderm formation. Together, these results provide for the first time a comprehensive molecular model connecting the transition from pluripotency to endoderm specification during mammalian development. -
The Reproductive System
27 The Reproductive System PowerPoint® Lecture Presentations prepared by Steven Bassett Southeast Community College Lincoln, Nebraska © 2012 Pearson Education, Inc. Introduction • The reproductive system is designed to perpetuate the species • The male produces gametes called sperm cells • The female produces gametes called ova • The joining of a sperm cell and an ovum is fertilization • Fertilization results in the formation of a zygote © 2012 Pearson Education, Inc. Anatomy of the Male Reproductive System • Overview of the Male Reproductive System • Testis • Epididymis • Ductus deferens • Ejaculatory duct • Spongy urethra (penile urethra) • Seminal gland • Prostate gland • Bulbo-urethral gland © 2012 Pearson Education, Inc. Figure 27.1 The Male Reproductive System, Part I Pubic symphysis Ureter Urinary bladder Prostatic urethra Seminal gland Membranous urethra Rectum Corpus cavernosum Prostate gland Corpus spongiosum Spongy urethra Ejaculatory duct Ductus deferens Penis Bulbo-urethral gland Epididymis Anus Testis External urethral orifice Scrotum Sigmoid colon (cut) Rectum Internal urethral orifice Rectus abdominis Prostatic urethra Urinary bladder Prostate gland Pubic symphysis Bristle within ejaculatory duct Membranous urethra Penis Spongy urethra Spongy urethra within corpus spongiosum Bulbospongiosus muscle Corpus cavernosum Ductus deferens Epididymis Scrotum Testis © 2012 Pearson Education, Inc. Anatomy of the Male Reproductive System • The Testes • Testes hang inside a pouch called the scrotum, which is on the outside of the body -
BODY CAVITIES and MESENTERY
73: BODY CAVITIES and MESENTERY We've already mentioned that all the organs in the body are wrapped in "bags" made of thin layers of connective tissue. These bags are often inside of other bags, or even inside of several bags. The largest bags define areas that we call body cavities. There are three main cavities: the thoracic cavity, the abdominal cavity and the pelvic cavity. The thoracic cavity is subdivided into three smaller cavities: the pleural cavity (containing the lungs), the mediastinum(in the middle), and the pericardial cavity (containing the heart). The pleural cavity is easy to understand because it simply contains the lungs. The pericardial cavity contains not only the heart itself, but the large blood vessels that come out of it, such as the aorta. The pericardial cavity is inside of the third cavity, the mediastinum. ("Media" means "middle" and "stinum" can refer to the "sternum," which is the bone that runs down the center of the ribcage.) The mediastinum contains not only the pericardial cavity but also part of the esophagus and trachea, the thymus (remember this organ from module 2 on the immune system?), and quite a few nerves and lymph nodes. The thin layers of connective tissues that surround these cavities are made primarily of collagen and elastin (produced by fibroblast cells) but they also contain some very tiny nerves and blood vessels, as well as cells that make serous fluid. As we've seen in the past few lessons, the diaphragm separates the thoracic cavity from the abdominal cavity. The abdominal cavity contains the stomach, the spleen, the tail of the pancreas, the last half of the duodenum, the small intestines, most of the large intestines, and the mesentery (thin layers of connective tissue that anchor the intestines to the back wall of the abdominal cavity). -
Dr. ALSHIKH YOUSSEF Haiyan
Dr. ALSHIKH YOUSSEF Haiyan General features The peritoneum is a thin serous membrane Consisting of: 1- Parietal peritoneum －lines the ant. Abdominal wall and the pelvis 2- Visceral peritoneum - covers the viscera 3- Peritoneal cavity - the potential space between the parietal and visceral layer of peritoneum - in male, is a closed sac - but in the female, there is a communication with the exterior through the uterine tubes, the uterus, and the vagina ▪ Peritoneum cavity divided into Greater sac Lesser sac Communication between them by the epiploic foramen The peritoneum The peritoneal cavity is the largest one in the body. Divided into tow sac : .Greater sac; extends from diaphragm down to the pelvis. Lesser Sac .Lesser sac or omental bursa; lies behind the stomach. .Both cavities are interconnected through the epiploic foramen(winslow ). .In male : the peritoneum is a closed sac . .In female : the sac is not completely closed because it Greater Sac communicates with the exterior through the uterine tubes, uterus and vagina. Peritoneum in transverse section The relationship between viscera and peritoneum Intraperitoneal viscera viscera is almost totally covered with visceral peritoneum example, stomach, 1st & last inch of duodenum, jejunum, ileum, cecum, vermiform appendix, transverse and sigmoid colons, spleen and ovary Intraperitoneal viscera Interperitoneal viscera Retroperitoneal viscera Interperitoneal viscera Such organs are not completely wrapped by peritoneum one surface attached to the abdominal walls or other organs. Example liver, gallbladder, urinary bladder and uterus Upper part of the rectum, Ascending and Descending colon Retroperitoneal viscera some organs lie on the posterior abdominal wall Behind the peritoneum they are partially covered by peritoneum on their anterior surfaces only Example kidney, suprarenal gland, pancreas, upper 3rd of rectum duodenum, and ureter, aorta and I.V.C The Peritoneal Reflection The peritoneal reflection include: omentum, mesenteries, ligaments, folds, recesses, pouches and fossae. -
Rectal Indomethacin Or I.V. Gabexate Mesylate As Prophylaxis for AP ERCP
European Review for Medical and Pharmacological Sciences 2017; 21: 5268-5274 Rectal indomethacin or intravenous gabexate mesylate as prophylaxis for acute pancreatitis post-endoscopic retrograde cholangiopancreatography V. GUGLIELMI, M. TUTINO, V. GUERRA, P. GIORGIO National Institute of Gastroenterology, “S. de Bellis” Research Hospital Castellana Grotte, Bari, Italy Abstract. – OBJECTIVE: We aimed to evaluate mechanisms of AP are obstruction of the com- the results in our case series of AP ERCP over mon bile duct by stones, and alcohol abuse. En- the last three years. The prophylaxis for acute doscopic retrograde cholangiopancreatography pancreatitis (AP) post-endoscopic retrograde (ERCP) is the most frequent iatrogenic cause. cholangiopancreatography (ERCP) consists of rectal indomethacin, but some studies are not Post-ERCP AP is the most common and fear concordant. some adverse event for this procedure. In the PATIENTS AND METHODS: We compared 241 United States this complication costs $150 mil- ERCP performed from January 2014 to February lion annually for American Healthcare2,3 and it 2015 with intravenous gabexate mesylate (Group is a common cause of endoscopy-related lawsu- A), with the 387 ERCP performed from March its against gastroenterologists in the world. It 2015 to December 2016 with rectal indometha- has a significant morbidity and rare mortality cin (Group B) as prophylaxis for AP post-ERCP. RESULTS: There were 8 (3.31%) AP post-ERCP rate. About 10% of post-ERCP AP is moderate in Group A vs. 4 (1.03%) in Group B. or severe. Post-ERCP severe AP is associated CONCLUSIONS: Rectal indomethacin shows a with a higher mortality than non-ERCP-indu- better statistically significant performance than ced pancreatitis, but without statistical eviden- intravenous gabexate mesylate in the prophylax- ce4. -
The Physical Mechanisms of Drosophila Gastrulation: Mesoderm and Endoderm Invagination
| FLYBOOK DEVELOPMENT AND GROWTH The Physical Mechanisms of Drosophila Gastrulation: Mesoderm and Endoderm Invagination Adam C. Martin1 Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142 ORCID ID: 0000-0001-8060-2607 (A.C.M.) ABSTRACT A critical juncture in early development is the partitioning of cells that will adopt different fates into three germ layers: the ectoderm, the mesoderm, and the endoderm. This step is achieved through the internalization of specified cells from the outermost surface layer, through a process called gastrulation. In Drosophila, gastrulation is achieved through cell shape changes (i.e., apical constriction) that change tissue curvature and lead to the folding of a surface epithelium. Folding of embryonic tissue results in mesoderm and endoderm invagination, not as individual cells, but as collective tissue units. The tractability of Drosophila as a model system is best exemplified by how much we know about Drosophila gastrulation, from the signals that pattern the embryo to the molecular components that generate force, and how these components are organized to promote cell and tissue shape changes. For mesoderm invagination, graded signaling by the morphogen, Spätzle, sets up a gradient in transcriptional activity that leads to the expression of a secreted ligand (Folded gastrulation) and a transmembrane protein (T48). Together with the GPCR Mist, which is expressed in the mesoderm, and the GPCR Smog, which is expressed uniformly, these signals activate heterotrimeric G-protein and small Rho-family G-protein signaling to promote apical contractility and changes in cell and tissue shape. A notable feature of this signaling pathway is its intricate organization in both space and time. -
Ligaments －Two-Layered Folds of Peritoneum That Attached the Lesser Mobile Solid Viscera to the Abdominal Wall
Ingegneria delle tecnologie per la salute Fondamenti di anatomia e istologia aa. 2019-20 Lesson 7. Digestive system and peritoneum Peritoneum, abdominal vessel and spleen PERITONEUM: General features = a thin serous membrane that line walls of abdominal and pelvic cavities and cover organs within these cavities •Parietal peritoneum －lines walls of abdominal and pelvic cavities •Visceral peritoneum －covers organs •Peritoneal cavity － potential space between parietal and visceral layer of peritoneum, in male, is a closed sac, but in female, there is a communication with exterior through uterine tubes, uterus, and vagina Function • Secretes a lubricating serous fluid that continuously moistens associated organs • Absorb • Support viscera Peritoneum Histology The peritoneum is a serosal membrane that consists of a single layer of mesothelial cells and is supported by a basement membrane. The layer is attached to the body wall and viscera by a glycosaminoglycan matrix that contains collagen fibers, vessels, nerves, macrophages, and fat cells. relationship between viscera and peritoneum • Intraperitoneal viscera －viscera completely surrounded by peritoneum, example, stomach, superior part of duodenum, jejunum, ileum, cecum, vermiform appendix, transverse and sigmoid colons, spleen and ovary • Interperitoneal viscera －most part of viscera surrounded by peritoneum, example, liver, gallbladder, ascending and descending colon, upper part of rectum, urinary bladder and uterus • Retroperitoneal viscera －some organs lie on the posterior abdominal