Embryonic & Fetal Development
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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. -
Risk Factors Associated with Maternal Age and Other Parameters in Assisted Reproductive Technologies - a Brief Review
Available online at www.pelagiaresearchlibrary.com Pelagia Research Library Advances in Applied Science Research, 2017, 8(2):15-19 ISSN : 0976-8610 CODEN (USA): AASRFC Risk Factors Associated with Maternal Age and Other Parameters in Assisted Reproductive Technologies - A Brief Review Shanza Ghafoor* and Nadia Zeeshan Department of Biochemistry and Biotechnology, University of Gujrat, Hafiz Hayat Campus, Gujrat, Punjab, Pakistan ABSTRACT Assisted reproductive technology is advancing at fast pace. Increased use of ART (Assisted reproductive technology) is due to changing living standards which involve increased educational and career demand, higher rate of infertility due to poor lifestyle and child conceivement after second marriage. This study gives an overview that how advancing age affects maternal and neonatal outcomes in ART (Assisted reproductive technology). Also it illustrates how other factor like obesity and twin pregnancies complicates the scenario. The studies find an increased rate of preterm birth .gestational hypertension, cesarean delivery chances, high density plasma, Preeclampsia and fetal death at advanced age. The study also shows the combinatorial effects of mother age with number of embryos along with number of good quality embryos which are transferred in ART (Assisted reproductive technology). In advanced age women high clinical and multiple pregnancy rate is achieved by increasing the number along with quality of embryos. Keywords: Reproductive techniques, Fertility, Lifestyle, Preterm delivery, Obesity, Infertility INTRODUCTION Assisted reproductive technology actually involves group of treatments which are used to achieve pregnancy when patients are suffering from issues like infertility or subfertility. The treatments can involve invitro fertilization [IVF], intracytoplasmic sperm injection [ICSI], embryo transfer, egg donation, sperm donation, cryopreservation, etc., [1]. -
The Effects of Alcohol in Newborns Efeitos Do Álcool No Recém-Nascido
REVIEW The effects of alcohol in newborns Efeitos do álcool no recém-nascido Maria dos Anjos Mesquita* ABSTRACT alcoólicas leva a prejuízos individuais, para a sua família e para The purpose of this article was to present a review of the effects toda a sociedade. Apesar disso, a dificuldade do seu diagnóstico e of alcohol consumption by pregnant mothers on their newborn. a inexperiência dos profissionais de saúde faz com que o espectro Definitions, prevalence, pathophysiology, clinical features, diagnostic dessas lesões seja pouco lembrado e até desconhecido. As lesões criteria, follow-up, treatment and prevention were discussed. A causadas pela ação do álcool no concepto são totalmente prevenidas search was performed in Medline, LILACS, and SciELO databases se a gestante não consumir bebidas alcoólicas durante a gestação. using the following terms: “fetus”, “newborn”, “pregnant woman”, Assim, é fundamental a detecção das mulheres consumidoras “alcohol”, “alcoholism”, “fetal alcohol syndrome”, and “alcohol- de álcool durante a gravidez e o desenvolvimento de programas related disorders”. Portuguese and English articles published from específicos de alerta sobre as consequências do álcool durante a 2000 to 2009 were reviewed. The effects of alcohol consumed by gestação e amamentação. pregnant women on newborns are extremely serious and occur frequently; it is a major issue in Public Health worldwide. Fetal alcohol Descritores: Bebidas alcoólicas/efeitos adversos; Feto; Recém-nascido; spectrum disorders cause harm to individuals, their families, and the Síndrome alcoólica fetal; Transtornos relacionados ao uso de álcool entire society. Nevertheless, diagnostic difficulties and inexperience of healthcare professionals result in such damage, being remembered rarely or even remaining uncovered. -
Pregnancy and Prenatal Development Chapter 4
Child Growth and Development Pregnancy and Prenatal Development Chapter 4 Prepared by: Debbie Laffranchini From: Papalia, Olds, Feldman Prenatal Development: Three Stages • Germinal stage – Zygote • Embryonic stage – Embryo • Fetal stage – Fetus • Principles of development: – Cephalocaudal* – Proximodistal* Germinal Stage • Fertilization to 2 weeks • Zygote divides – Mitosis – Within 24 hours, 64 cells – Travels down the fallopian tube, approximately 3 – 4 days – Changes to a blastocyst – Cell differentiation begins • Embryonic disk – Differentiates into two layers » Ectoderm: outer layer of skin, nails, hair, teeth, sensory organs, nervous system, including brain and spinal cord » Endoderm: digestive system, liver, pancreas, salivary glands, respiratory system – Later a middle layer, mesoderm, will develop into skin, muscles, skeleton, excretory and circulatory systems – Implants about the 6th day after fertilization – Only 10% - 20% of fertilized ova complete the task of implantation • 800 billion cells eventually Germinal Stage (cont) • Blastocyst develops – Amniotic sac, outer layers, amnion, chorion, placenta and umbilical cord – Placenta allows oxygen, nourishment, and wastes to pass between mother and baby • Maternal and embryonic tissue • Placenta filters some infections • Produces hormones – To support pregnancy – Prepares mother’s breasts for lactation – Signals contractions for labor – Umbilical cord is connected to embryo • Mother’s circulatory system not directly connected to embryo system, no blood transfers Embryonic Stage: -
Introduction to Plant Embryology Dr
Introduction to Plant embryology Dr. Pallavi J.N.L. College Khagaul Plant Embryology • Embryology is the study of structure and development of embryo, including the structure and development of male and female reproductive organs, fertilisation and similar other processes. • Father of Indian Plant empryology- Panchanan Maheshwari • Plant embryogenesis is a process that occurs after the fertilization of an ovule to produce a fully developed plant embryo. This is a pertinent stage in the plant life cycle that is followed by dormancy and germination. • The zygote produced after fertilization, must undergo various cellular divisions and differentiations to become a mature embryo. An end stage embryo has five major components including the shoot apical meristem, hypocotyl, root meristem, root cap, and cotyledons. Unlike animal embryogenesis, plant embryogenesis results in an immature form of the plant, lacking most structures like leaves, stems, and reproductive structures. • The Phanerogams (the flowering-plants) are also called spermatophytes (the seed bearing plants). These plants propagate mainly through seeds. The seed is a structure in which the embryo is enclosed. Adjacent to the embryo, foods are stored either inside the endosperm (albuminous) or in cotyledon (exalbuminous) for future use. Life cycle of flowering plants • Alternation between a dominant sporophytic generation and a highly reduced gametophytic generation. Dominant sporophytic generation is diploid and reduced gaThe normal sexual cycle (amphimixing) involves two important processes: • (i) Meiosis and • (ii) Fertilization • In meiosis also known as reduction division, a diploid sporophytic cell spore mother cell) • gets converted into four haploid gametophytic cells. (“2n” number of chromosomes becomes half i.e. “n” number of chromosome) gametophytic generation is haploid. -
Extended Abstract
Extended abstract Effect of intrauterine development and nutritional status on perinatal, intrauterine and neonatal mortality 1 Péter Berkő, 2 Kálmán Joubert, 3 Éva Gárdos, 4 Gyula Gyenis 1Faculty of Healthcare, Miskolc University, BAZ County and University Teaching Hospital Miskolc, Hungary, - 2Demographic Research Institute, Hungarian Central Statistical Office, Budapest, - 3Hungarian Central Statistical Office, Budapest, - 4Department of Biological Anthropology, Faculty of Science, Eötvös Lorand University, Budapest, Hungary At least 50-60% of 3 million of intrauterine and near 4 million deaths that occur worldwide every year are associated with low birth weight, caused by intrauterine growth restriction, preterm delivery, and genetic abnormalities. Fetal growth restriction is the second leading cause of perinatal morbidity and mortality. The authors study to what extent bodily development and nutritional status influence the viability, or perinatal mortality of foetuses and neonates. In the present study the authors describe their novel method, the MDN system (MDN: Maturity, Development, Nutritional status) and its application: 1./ to determine the nutritional status of a neonate on the basis of its gestational age, length and weight development considered simultaneously; - 2./ to differentiate the most viable and the most endangered neonates on the basis of their development and nutritional status; - 3./ to demonstrate the influence of a neonate’s nutritional status by the gestational age on its perinatal mortality. Method – the MDN system The authors have developed a new method, the MDN system (MDN: Maturity, Development, Nutritional status) to determine the weight and length standard positions of neonates in relation to reference standards on the basis of their gestational ages, birth weights and lengths. -
Evolution of Oviductal Gestation in Amphibians MARVALEE H
THE JOURNAL OF EXPERIMENTAL ZOOLOGY 266394-413 (1993) Evolution of Oviductal Gestation in Amphibians MARVALEE H. WAKE Department of Integrative Biology and Museum of Vertebrate Zoology, University of California,Berkeley, California 94720 ABSTRACT Oviductal retention of developing embryos, with provision for maternal nutrition after yolk is exhausted (viviparity) and maintenance through metamorphosis, has evolved indepen- dently in each of the three living orders of amphibians, the Anura (frogs and toads), the Urodela (salamanders and newts), and the Gymnophiona (caecilians). In anurans and urodeles obligate vivi- parity is very rare (less than 1%of species); a few additional species retain the developing young, but nutrition is yolk-dependent (ovoviviparity) and, at least in salamanders, the young may be born be- fore metamorphosis is complete. However, in caecilians probably the majority of the approximately 170 species are viviparous, and none are ovoviviparous. All of the amphibians that retain their young oviductally practice internal fertilization; the mechanism is cloaca1 apposition in frogs, spermato- phore reception in salamanders, and intromission in caecilians. Internal fertilization is a necessary but not sufficient exaptation (sensu Gould and Vrba: Paleobiology 8:4-15, ’82) for viviparity. The sala- manders and all but one of the frogs that are oviductal developers live at high altitudes and are subject to rigorous climatic variables; hence, it has been suggested that cold might be a “selection pressure” for the evolution of egg retention. However, one frog and all the live-bearing caecilians are tropical low to middle elevation inhabitants, so factors other than cold are implicated in the evolu- tion of live-bearing. -
Management of Neonates Born at ≤34 6/7 Weeks' Gestation with Suspected Or Proven Early-Onset Bacterial Sepsis Karen M
CLINICAL REPORT Guidance for the Clinician in Rendering Pediatric Care ≤ ’ Management of Neonates Born at 34 Karen M. Puopolo, MD, PhD, FAAP, a, b William E. Benitz, MD, FAAP, c Theoklis E. Zaoutis, MD, MSCE, FAAP, a, d 6/7COMMITTEE ONWeeks FETUS AND NEWBORN, GestationCOMMITTEE ON INFECTIOUS DISEASES With Suspected or Proven Early-Onset Bacterial Sepsis Early-onset sepsis (EOS) remains a serious and often fatal illness among abstract infants born preterm, particularly among newborn infants of the lowest gestational age. Currently, most preterm infants with very low birth weight are treated empirically with antibiotics for risk of EOS, often for prolonged aDepartment of Pediatrics, Perelman School of Medicine, University periods, in the absence of a culture-confirmed infection. Retrospective of Pennsylvania, Philadelphia, Pennsylvania; bChildren’s Hospital of studies have revealed that antibiotic exposures after birth are associated Philadelphia, and dRoberts Center for Pediatric Research, Philadelphia, Pennsylvania; and cDivision of Neonatal and Developmental Medicine, with multiple subsequent poor outcomes among preterm infants, making the Department of Pediatrics, School of Medicine, Stanford University, Palo risk/benefit balance of these antibiotic treatments uncertain. Gestational Alto, California age is the strongest single predictor of EOS, and the majority of preterm This document is copyrighted and is property of the American Academy of Pediatrics and its Board of Directors. All authors have births occur in the setting of other factors associated with risk of EOS, filed conflict of interest statements with the American Academy of Pediatrics. Any conflicts have been resolved through a process making it difficult to apply risk stratification strategies to preterm infants. -
Bivariate Analysis of Birth Weight and Gestational Age Depending on Environmental Exposures: Bayesian Distributional Regression with Copulas
Bivariate Analysis of Birth Weight and Gestational Age Depending on Environmental Exposures: Bayesian Distributional Regression with Copulas Jonathan Rathjens1, Arthur Kolbe2, Jürgen Hölzer2, Katja Ickstadt1, and Nadja Klein3 1Technische Universität Dortmund, 2Ruhr-Universität Bochum, 3Humboldt-Universität zu Berlin April 30, 2021 Abstract In this article, we analyze perinatal data with birth weight (BW) as primarily interesting response variable. Gestational age (GA) is usually an important covariate and included in polynomial form. However, in opposition to this univariate regression, bivariate modeling of BW and GA is recommended to distinguish effects on each, on both, and between them. Rather than a parametric bivariate distribution, we apply conditional copula regression, where marginal distributions of BW and GA (not necessarily of the same form) can be estimated independently, and where the dependence structure is modeled conditional on the covariates separately from these marginals. In the resulting distributional regression models, all parame- ters of the two marginals and the copula parameter are observation-specific. Besides biometric and obstetric information, data on drinking water contamination and maternal smoking are in- cluded as environmental covariates. While the Gaussian distribution is suitable for BW, the skewed GA data are better modeled by the three-parametric Dagum distribution. The Clay- ton copula performs better than the Gumbel and the symmetric Gaussian copula, indicating lower tail dependence (stronger dependence when both variables are low), although this non- linear dependence between BW and GA is surprisingly weak and only influenced by Cesarean arXiv:2104.14243v1 [stat.ME] 29 Apr 2021 section. A non-linear trend of BW on GA is detected by a classical univariate model that is polynomial with respect to the effect of GA. -
Embryology BOLK’S COMPANIONS FOR‑THE STUDY of MEDICINE
Embryology BOLK’S COMPANIONS FOR‑THE STUDY OF MEDICINE EMBRYOLOGY Early development from a phenomenological point of view Guus van der Bie MD We would be interested to hear your opinion about this publication. You can let us know at http:// www.kingfishergroup.nl/ questionnaire/ About the Louis Bolk Institute The Louis Bolk Institute has conducted scientific research to further the development of organic and sustainable agriculture, nutrition, and health care since 1976. Its basic tenet is that nature is the source of knowledge about life. The Institute plays a pioneering role in its field through national and international collaboration by using experiential knowledge and by considering data as part of a greater whole. Through its groundbreaking research, the Institute seeks to contribute to a healthy future for people, animals, and the environment. For the Companions the Institute works together with the Kingfisher Foundation. Publication number: GVO 01 ISBN 90-74021-29-8 Price 10 € (excl. postage) KvK 41197208 Triodos Bank 212185764 IBAN: NL77 TRIO 0212185764 BIC code/Swift code: TRIONL 2U For credit card payment visit our website at www.louisbolk.nl/companions For further information: Louis Bolk Institute Hoofdstraat 24 NL 3972 LA Driebergen, Netherlands Tel: (++31) (0) 343 - 523860 Fax: (++31) (0) 343 - 515611 www.louisbolk.nl [email protected] Colofon: © Guus van der Bie MD, 2001, reprint 2011 Translation: Christa van Tellingen and Sherry Wildfeuer Design: Fingerprint.nl Cover painting: Leonardo da Vinci BOLK FOR THE STUDY OF MEDICINE Embryology ’S COMPANIONS Early Development from a Phenomenological Point of view Guus van der Bie MD About the author Guus van der Bie MD (1945) worked from 1967 to Education, a project of the Louis Bolk Instituut to 1976 as a lecturer at the Department of Medical produce a complement to the current biomedical Anatomy and Embryology at Utrecht State scientific approach of the human being. -
FASD Effects of Alcohol on a Fetus
EFFECTS OF ALCOHOL ON A FETUS “Of all the substances of abuse (including cocaine, heroin, and marijuana), alcohol produces by far the most serious neurobehavioral effects in the fetus.” —Institute of Medicine Report to Congress, 19961 Prenatal exposure to alcohol can damage a fetus at any time, causing problems that persist throughout the individual’s life. There is no known safe level of alcohol use in pregnancy. WHAT IS THE SCOPE OF THE PROBLEM? identified in virtually every part of the body, including the brain, face, eyes, ears, heart, kidneys, and bones. No Alcohol is one of the most dangerous teratogens, which single mechanism can account for all the problems that are substances that can damage a developing fetus.1 Every alcohol causes. Rather, alcohol sets in motion many time a pregnant woman has a drink, her unborn child processes at different sites in the developing fetus: has one, too. Alcohol, like carbon monoxide from cigarettes, passes easily through the placenta from the • Alcohol can trigger cell death in a number of ways, mother's bloodstream into her baby's blood (See Figure causing different parts of the fetus to develop abnormally. 1)—and puts her fetus at risk of having a fetal alcohol • Alcohol can disrupt the way nerve cells develop, travel spectrum disorder (FASD). The blood alcohol level to form different parts of the brain, and function. (BAC) of the fetus becomes equal to or greater than the blood alcohol level of the mother. Because the fetus • By constricting the blood vessels, alcohol interferes with cannot break down alcohol the way an adult can, its BAC blood flow in the placenta, which hinders the delivery 2 remains high for a longer period of time. -
The Stunted Development of in Vitro Fertilization in the United States, 1975-1992
EMBRYONIC POLICIES: THE STUNTED DEVELOPMENT OF IN VITRO FERTILIZATION IN THE UNITED STATES, 1975-1992 Erin N. McKenna A Thesis Submitted to the Graduate College of Bowling Green State University in partial fulfillment of the requirements for the degree of MASTER OF ARTS May 2006 Committee: Dr. Leigh Ann Wheeler, Advisor Dr. Walter Grunden ii Abstract The federal government’s failure to fund research on in vitro fertilization has had an important legacy and significant consequences in the United States. Due to the dismantling of the Ethics Advisory Board in 1980, no government funding was provided for research for in vitro fertilization (IVF), embryo transfer (ET), and gamete intra-fallopian transfer (GIFT). The lack of government funding, regulation, and involvement has resulted in the false advertising of higher success rates to lure patients into the infertility specialists’ offices. In their desperation to have children, consumers of such medical technologies paid exorbitant fees that often remained uncovered by insurance companies. The federal government enacted legislation in 1992 attempting to alleviate some of the aspects of exploitation of the consumer-patient. The government’s recognition of the importance of such procedures was hit and miss, though, much like the reproductive technology itself. The legacy is one that has resulted in American citizens who now turn to developing countries such as Israel and India, where the treatment is drastically cheaper and often more effective. I attempt to explain the federal government’s response to New Reproductive Technologies (NRTs), beginning with in vitro fertilization, thus exploring why and how this debate has inextricably been linked to the ongoing abortion debate.