DOCSLIB.ORG

Embryology, Histology, and Anatomy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Embryology, Histology, and Anatomy EMBRYOLOGY, HISTOLOGY, 1 AND ANATOMY EMBRYOLOGY intimate contact with the portal mesenchyme At the beginning of fetal development (to- surrounding a portal vein branch (2). In the ward the latter part of the third week of gesta- weeks that follow, certain parts of the ductal tion), the hepatic diverticulum buds from the plates are duplicated by a second layer of cells, ventral foregut. The hepatic diverticulum then to become double-layered ductal plates, which gives rise to the transverse septum (septum then dilate to form cylindrical structures to be transversum), a structure situated between integrated into the mesenchyme of the newly the pericardial and peritoneal cavities (1,2). formed portal region (fig. 1-1). When they are Mesenchymal elements of the transverse sep- integrated into the portal space, the immature tum, which already exist, are invested by liver tubules evolve into bile ducts that are embraced parenchyma formed from hepatic endodermal by connective tissue and gradually situated in cells (also known as hepatoblasts) of the he- their usual location in the portal tracts as the patic diverticulum to give rise to the liver buds portal tracts increase in size (2,7–9). (3). During fetal development the liver buds function as a hematopoietic organ, which is GROSS ANATOMY composed of hepatocytic cords, venous-sinusoi- The liver can be divided into the right and dal plexus, and hematopoietic precursor cells, left lobes by the middle hepatic vein and a plane including Kupffer cells (macrophages residing between the inferior vena cava and the gallblad- in liver). The umbilical vein supplies most of der fossa. Anteriorly, this division is visible by the blood during development of the liver. The the falciform ligament. Viewed from the under remaining smaller amount of blood is supplied surface, there are also the quadrate lobe in the by the portal vein and hepatic artery. vicinity of the gallbladder fossa and the caudate During fetal development, the placenta ex- lobe which in part encases the vena cava. ecutes the major functions performed by the There are dual afferent blood supplies in adult liver, including the absorption of nutri- the liver: hepatic artery and portal vein. The ents and the excretion of bile containing waste hepatic artery (branches from the celiac artery) products; bile secretion by fetal liver is negligible transports 30 to 40 percent and the portal vein before birth. Nonetheless, the fetal liver produc- (drains the intestine) transports up to 70 per- es alpha-fetoprotein and other plasma proteins, cent of the oxygenated blood to the liver. The synthesizes bile acids, and stores fat, glycogen, sinusoids then carry blood from hepatic arteries iron, and copper. and portal veins to the terminal hepatic venules, The anterior portion of the hepatic diver- and subsequently through the hepatic vein to ticulum forms the liver and intrahepatic bile the inferior vena cava. ducts, while the posterior portion gives rise Functionally, the liver is better divided into to the gallbladder and extrahepatic bile ducts eight segments based on the blood supply, (2,4–6). The ultimate formation of intrahepatic known as the Couinaud classification, or Cou- bile ducts occurs late during development, and is inaud scheme (fig. 1-2). The segments are num- completed after birth, during the first year of life. bered in Roman numerals I to VIII. Segment I The development of small intrahepatic bile ducts essentially represents the caudate lobe, which begins when the ductal plate is formed, which drains directly into the inferior vena cava. Seg- is a single-layered sheath of small flat epithelial ments II to VIII are then numbered in a clockwise cells assembled by the periportal hepatoblasts in manner in a frontal plane beginning superiorly 1 Tumors of the Liver Figure 1-1 FETAL LIVER Left: The embryonic ductal plate, composed of cytokeratin-rich cells, forms a layer that surrounds the portal area. This immunostain for cytokeratin (CK) 18 shows that the ductal plate is discontinuous and in a few places forms a double layer of cells with small lumina. Right: Higher magnification of another portal area shows the bile duct forming from the ductal plate, which will eventually disappear as the liver grows. Figure 1-2 SEGMENTAL ANATOMY OF THE LIVER The segments, designated by Ro- man numerals, can be resected sur gically because each is sup- plied by a major branch of the hepatic artery and portal vein and drained by a major tributary of the hepatic vein. from the left lobe. These segments are bounded ing to the Couinaud scheme allows the surgical by the three main branches of the hepatic veins: removal of a single segment, or two or more the left, middle, and right hepatic veins. Each adjacent segments en bloc, in such a fashion to segment drains into branches of the hepatic veins avoid damaging the remaining segments. The and then into the inferior vena cava. Overall, seg- Couinaud scheme also serves as a common ter- ments I to IV represent the functional left lobe, minology for communicating among physicians whereas segments V to VIII are considered the of different disciplines: surgeons, hepatologists, functional right lobe. Division of the liver accord- oncologists, radiologists, and pathologists (10). 2 Embryology, Histology, and Anatomy Figure 1-3 HISTOLOGIC ORGANIZATION OF THE LIVER Left: Hepatic Architecture. Two views of the architecture of the liver as seen in microscopic sections. The lobules have a central vein at the center and portal spaces at the corners. A cross section of an acinus superimposed on two lobules shows that zone 3 tends to be centrilobular, zone 2 midzonal, and zone 1 periportal, but all three are crescent shaped and may extend into other parts of the classic lobule. Bottom: Liver Blood Flow. Figure from “Gastro intestinal Tract—Liver Development” from embryology. med.unsw.edu.au. portal tracts at the center. The spherical area of HISTOLOGIC ORGANIZATION those hepatocytes surrounding the portal tract The liver is structurally organized into pa- is referred to as zone 1, which has the richest renchymal, vascular, bile ductal, and interstitial oxygenated blood. The area outside of zone 1 components (11). Traditionally, the smallest is referred to as zone 2. Zone 3 is further out, functional unit has been conceptualized as corresponding to the region surrounding the the hepatic lobule or three dimensionally as terminal hepatic vein, where the oxygen con- the hepatic acinus, as defined by Rappaport tent in blood is the lowest (fig. 1-3). (12). Most oxygenated blood flows from the The two-dimensional concept of the lobule, terminal branches of portal veins and hepatic as seen on slides, serves the purpose of histo- arteries in the portal tracts, via the sinusoids to logic visualization, but zonal subdivision of the supply the hepatocytes, and finally draining acinus incorporates the physiologic concept into the terminal branches of the hepatic (cen- into histologic organization and facilitates the tral) veins at the peripheral part of the acinus recognition of certain liver injury patterns. (11). The acinus can also be conceptualized as These patterns include the gradual increasing a three-dimensional spherical structure with vulnerability to ischemic and toxic/metabolic 3 Tumors of the Liver Figure 1-4 HEPATOCYTES AND ENDOTHELIAL CELLS Left: Normal hepatocytes are polyhedral cells arranged in plates that are one cell thick. They have granular, eosinophilic cytoplasm and usually one nucleus. The sinusoids between the hepatocytes are lined by inconspicuous endothelial cells. Right: The hepatocytic plates are normally one cell layer in thickness and are separated by the sinusoidal space (reticulin stain). injuries from zone 1 through zone 2 to zone 3, Bile ductules and canals of Hering are struc- as well as the distinction between adult nonal- tures at the periphery of the portal tracts and coholic steatohepatitis (zone 3 accentuated) and are not conspicuous by hematoxylin and eosin pediatric nonalcoholic steatohepatitis (zone 1 (H&E) stain in normal liver. They are the con- accentuated) (13–15). duits between the biliary tree and hepatocyte Hepatocytes are formed in plates of one cell canaliculi. The canals of Hering drain bile from in thickness, which can be highlighted by a bile canaliculi into bile ductules, and then into reticulin stain (fig. 1-4, right). The hepatocytic the interlobular bile ducts. Canals of Hering plates are organized in a radial fashion between are important for liver regeneration since the the portal tracts and terminal hepatic venules hepatic progenitor cells reside here (16,17). (fig. 1-5), and are separated by sinusoids lined by endothelial cells, with oxygenated blood HISTOLOGY flowing from the portal tracts to the terminal Cells of the Liver hepatic venules. The radial alignment is most pronounced in the hepatocyte plates surround- Hepatocytes. Hepatocytes, which originate ing the terminal hepatic venules. In normal from endoderm, comprise the primary cell pop- liver, the portal tracts are composed of at least ulation in liver, accounting for 75 to 80 percent one hepatic artery branch, one portal vein of the liver volume (18). They are hexagonal or branch, and one interlobular bile duct (fig. 1-6). polyhedral in cross section, and have an eosin- The boundary between the portal tracts and the ophilic cytoplasm containing a centrally placed first layer of hepatocytes in the parenchyma is round nucleus; occasional hepatocytes may be termed the limiting plate. binucleatic. In the adult liver, hepatocytes are 4 Embryology, Histology, and Anatomy Figure 1-5 Figure 1-6 HEPATIC ARCHITECTURE PORTAL TRACT Plates of hepatocytes extend from the portal area (lower A normal portal tract has at least one portal vein, one left) to the terminal hepatic venule or central vein (upper hepatic artery, and one bile duct. The interlobular bile duct right). Blood that enters the liver through branches of the is approximately the same diameter as the hepatic artery portal vein and hepatic artery perfuses the sinusoids and and is approximately the same distance as its own diameter exits through tributaries of the hepatic vein.
Load more

Recommended publications
  • Cell Biology and Fundamentals in Histology - En-Cours-2018-Liepr1004 Liepr1004 Cell Biology and Fundamentals in 2018 Histology
    Université catholique de Louvain - Cell biology and fundamentals in histology - en-cours-2018-liepr1004 liepr1004 Cell biology and fundamentals in 2018 histology 5 credits 45.0 h Q2 Teacher(s) Behets Wydemans Catherine ;Henriet Patrick ; Language : French Place of the course Louvain-la-Neuve Main themes The major themes are : - Characteristics common to all living species - The human cell, its functioning and division - Classical, evolutive and molecular genetics - Cellular bases in sexual reproduction - The differents cell types and their organisation in tissues - The major steps in human embryonic development Aims By the end of the module, students should understand the bases of unicity and diversity in the living world. They will know the structure and functioning of human cell and genome as well as the mechanisms of 1 cell division and embryonic development. Moreover, they will know the structure of the major types of human tissues. - - - - The contribution of this Teaching Unit to the development and command of the skills and learning outcomes of the programme(s) can be accessed at the end of this sheet, in the section entitled “Programmes/courses offering this Teaching Unit”. Content (auteurs - titulaires actuels) : P. Henriet and Ph. van den Bosch de Aguilar 1. UNICITY IN THE LIVING WORLD 2. THE HUMAN CELL 3. DIVERSITY IN THE LIVING WORLD 4. MOLECULAR GENETICS 5. CELL DIVISION 6. GAMETOGENESIS AND FERTILIZATION 7. INTRODUCTION TO HUMAN EMBRYOLOGY Histology 1. EPITHELIAL TISSUE 2. CONNECTIVE TISSUE 3. BLOOD TISSUE 4. MUSCLE TISSUE
    [Show full text]
  • Immune Response and Histology of Humoral Rejection in Kidney
    Document downloaded from http://www.elsevier.es, day 23/05/2017. This copy is for personal use. Any transmission of this document by any media or format is strictly prohibited. n e f r o l o g i a 2 0 1 6;3 6(4):354–367 Revista de la Sociedad Española de Nefrología www.revistanefrologia.com Review Immune response and histology of humoral rejection in kidney transplantation a,∗ a b a Miguel González-Molina , Pedro Ruiz-Esteban , Abelardo Caballero , Dolores Burgos , a c a a Mercedes Cabello , Miriam Leon , Laura Fuentes , Domingo Hernandez a Nephrology Department, Regional University Hospital of Malaga, Malaga University, IBIMA, REDINREN RD12/0021/0015, Malaga, Spain b Immunology Department, Regional University Hospital of Malaga, Malaga University, IBIMA, REDINREN RD12/0021/0015, Malaga, Spain c Pathology Department, Regional University Hospital of Malaga, Malaga University, IBIMA, REDINREN RD12/0021/0015, Malaga, Spain a r t i c l e i n f o a b s t r a c t Article history: The adaptive immune response forms the basis of allograft rejection. Its weapons are direct Received 4 June 2015 cellular cytotoxicity, identified from the beginning of organ transplantation, and/or anti- Accepted 26 March 2016 bodies, limited to hyperacute rejection by preformed antibodies and not as an allogenic Available online 3 June 2016 response. This resulted in allogenic response being thought for decades to have just a cellu- lar origin. But the experimental studies by Gorer demonstrating tissue damage in allografts Keywords: due to antibodies secreted by B lymphocytes activated against polymorphic molecules were Immune response disregarded.
    [Show full text]
  • Satellitosis, a Crosstalk Between Neurons, Vascular Structures and Neoplastic Cells in Brain Tumours; Early Manifestation of Invasive Behaviour
    cancers Review Satellitosis, a Crosstalk between Neurons, Vascular Structures and Neoplastic Cells in Brain Tumours; Early Manifestation of Invasive Behaviour Prospero Civita 1,2,* , Ortenzi Valerio 3 , Antonio Giuseppe Naccarato 3 , Mark Gumbleton 2 and Geoffrey J. Pilkington 1,2,4,* 1 Brain Tumour Research Centre, Institute of Biological and Biomedical Sciences (IBBS), School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK 2 School of Pharmacy and Pharmaceutical Sciences, College of Biomedical and Life Sciences, Cardiff University, Cardiff CF10 3NB, UK; gumbleton@cardiff.ac.uk 3 Department of Translational Research and New Technologies in Medicine and Surgery, Pisa University Hospital, 56100 Pisa, Italy; [email protected] (O.V.); [email protected] (A.G.N.) 4 Division of Neuroscience, Department of Basic and Clinical Neuroscience, Institute of Psychiatry & Neurology, King’s College London, London SE5 9RX, UK * Correspondence: CivitaP@cardiff.ac.uk (P.C.); geoff[email protected] (G.J.P.) Received: 9 November 2020; Accepted: 4 December 2020; Published: 11 December 2020 Simple Summary: This article reviews the concept of cellular satellitosis as originally described histologically by Santiago Ramón y Cajal in 1899 and Hans Joachim Scherer, more specifically in the context of glioblastoma invasiveness, during the early part of the 20th century. With the advent of new and emerging molecular technologies in the 21st century, the significance of both vascular and neuronal satellitosis by neoplastic cells offers intriguing possibilities into further clarifying the development, pathobiology and therapy of malignant glioma through closer investigation into the nature of these histological hallmarks.
    [Show full text]
  • Basic Histology (23 Questions): Oral Histology (16 Questions
    Board Question Breakdown (Anatomic Sciences section) The Anatomic Sciences portion of part I of the Dental Board exams consists of 100 test items. They are broken up into the following distribution: Gross Anatomy (50 questions): Head - 28 questions broken down in this fashion: - Oral cavity - 6 questions - Extraoral structures - 12 questions - Osteology - 6 questions - TMJ and muscles of mastication - 4 questions Neck - 5 questions Upper Limb - 3 questions Thoracic cavity - 5 questions Abdominopelvic cavity - 2 questions Neuroanatomy (CNS, ANS +) - 7 questions Basic Histology (23 questions): Ultrastructure (cell organelles) - 4 questions Basic tissues - 4 questions Bone, cartilage & joints - 3 questions Lymphatic & circulatory systems - 3 questions Endocrine system - 2 questions Respiratory system - 1 question Gastrointestinal system - 3 questions Genitouirinary systems - (reproductive & urinary) 2 questions Integument - 1 question Oral Histology (16 questions): Tooth & supporting structures - 9 questions Soft oral tissues (including dentin) - 5 questions Temporomandibular joint - 2 questions Developmental Biology (11 questions): Osteogenesis (bone formation) - 2 questions Tooth development, eruption & movement - 4 questions General embryology - 2 questions 2 National Board Part 1: Review questions for histology/oral histology (Answers follow at the end) 1. Normally most of the circulating white blood cells are a. basophilic leukocytes b. monocytes c. lymphocytes d. eosinophilic leukocytes e. neutrophilic leukocytes 2. Blood platelets are products of a. osteoclasts b. basophils c. red blood cells d. plasma cells e. megakaryocytes 3. Bacteria are frequently ingested by a. neutrophilic leukocytes b. basophilic leukocytes c. mast cells d. small lymphocytes e. fibrocytes 4. It is believed that worn out red cells are normally destroyed in the spleen by a. neutrophils b.
    [Show full text]
  • Liver • Gallbladder
    NORMAL BODY Microscopic Anatomy! Accessory Glands of the GI Tract,! lecture 2! ! • Liver • Gallbladder John Klingensmith [email protected] Objectives! By the end of this lecture, students will be able to: ! • trace the flow of blood and bile within the liver • describe the structure of the liver in regard to its functions • indicate the major cell types of the liver and their functions • distinguish the microanatomy of exocrine and endocrine function by the hepatocytes • explain the functional organization of the gallbladder at the cellular level (Lecture plan: overview of structure and function, then increasing resolution of microanatomy and cellular function) Liver and Gallbladder Liver October is “Liver Awareness Month” -- http://www.liverfoundation.org Liver • Encapsulated by CT sheath and mesothelium • Lobes largely composed of hepatocytes in parenchyma • Receives blood from small intestine and general circulation Major functions of the liver • Production and secretion of digestive fluids to small intestine (exocrine) • Production of plasma proteins and lipoproteins (endocrine) • Storage and control of blood glucose • Detoxification of absorbed compounds • Source of embyronic hematopoiesis The liver lobule • Functional unit of the parenchyma • Delimited by CT septa, invisible in humans (pig is shown) • Surrounds the central vein • Bordered by portal tracts Central vein, muralia and sinusoids Parenchyma: Muralia and sinusoids • Hepatocyte basolateral membrane faces sinusoidal lumen • Bile canaliculi occur between adjacent hepatocytes • Cords anastomose Vascularization of the liver • Receives veinous blood from small intestine via portal vein • Receives freshly oxygenated blood from hepatic artery • Discharges blood into vena cava via hepatic vein Blood flow in the liver lobes • flows in via the portal vein and hepatic artery • oozes through the liver lobules to central veins • flows out via the hepatic vein Portal Tract! (aka portal triad) • Portal venule • Hepatic arteriole • Bile duct • Lymph vessel • Nerves • Connective tissue Central vein! (a.k.a.
    [Show full text]
  • The Histology of the Neuromuscular Junction In
    75 THE HISTOLOGY OF THE NEUROMUSCULAR JUNCTION Downloaded from https://academic.oup.com/brain/article/84/1/75/372729 by guest on 27 September 2021 IN DYSTROPHIA MYOTONICA BY VIOLET MACDERMOT Department of Neurology, St. Thomas' Hospital, London, S.E.I (1) INTRODUCTION DYSTROPJHC MYOTONICA is a familial disease affecting males and females, usually presenting in adult life, characterized by muscular wasting and weakness together with certain other features. The muscles mainly in- volved are the temporal, masseter, facial, sternomastoid and limb muscles, in the latter those mainly affected being peripheral in distribution. A widespread disorder of muscular contraction, myotonia, is also present but is noticed chiefly in the tongue and in the muscles involved in grasping. The other features of the condition are some degree of mental defect, dysphonia, cataracts, frontal baldness, sparse body hair and testicular atrophy. Any of the manifestations of the disease may be absent and the order of presentation of symptoms is variable. The myotonia may precede muscular wasting by many years or may occur independently. In those muscles which are severely wasted the myotonia tends to disappear. The interest of dystrophia myotonica lies in the peculiar distribution of muscle involvement and in the combination of a disorder of muscle function with endocrine and other dysplasic features. The results of histological examination of biopsy and post-mortem material have been described and reviewed by numerous workers, notably Steinert (1909), Adie and Greenfield (1923), Keschner and Davison (1933), Hassin and Kesert (1948), Wohlfart (1951), Adams, Denny-Brown and Pearson (1953), Greenfield, Shy, Alvord and Berg (1957).
    [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]
  • Isolation of Small Polarized Bile Duct Units A
    Proc. Natl. Acad. Sci. USA Vol. 92, pp. 6527-6531, July 1995 Physiology Isolation of small polarized bile duct units A. MENNONE*, D. ALVAROt, W. CHO*, AND J. L. BOYER*t *Department of Medicine and Liver Center, Yale University School of Medicine, P.O. Box 208019, 333 Cedar Street, New Haven, CT (06520-8019; and tViale Dell'Universita' 37, 00185 Rome, Italy Communicated by Edward Adelberg, New Haven, CT, February 27, 1995 ABSTRACT Fragments of small interlobular bile ducts BB salt, forskolin, dideoxyforskolin, and N6,2'-O-dibutyryl- averaging 20 ,um in diameter can be isolated from rat liver. adenosine 3' :5 '-cyclic monophosphate (dibutyryl cAMP; These isolated bile duct units form luminal spaces that are Bt2cAMP) were purchased from Sigma. 2,7-Bis(carboxy- impermeant to dextran-40 and expand in size when cultured methyl)-5-(and-6)-carboxyfluorescein, acetomethyl ester in 10 ,uM forskolin for 24-48 hr. Secretion is Cl- and HCO3 (BCECF-AM), and H2DIDS were obtained from Molecular dependent and is stimulated by forskolin > dibutyryl cAMP Probes. Matrigel was from Collaborative Research, collage- > secretin but not by dideoxyforskolin, as assessed by video nase D was from Boehringer Mannheim Biochemicals, and imaging techniques. Secretin stimulates Cl-/HCOi exchange Pronase was from Calbiochem. Liebowitz-15 (L-15), minimum activity, and intraluminal pH increases after forskolin ad- essential medium (MEM), a-MEM, L-glutamine, gentamicin, ministration. These studies establish that small polarized and fetal calf serum were from GIBCO. N-(,y-1-Glutamyl)-4- physiologically intact interlobular bile ducts can be isolated methoxy-2-naphthylamide was obtained from Polyscience.
    [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]
  • The Liver Lecture
    Gross Anatomy Liver • The largest single organ in the human body. • In an adult, it weighs about three pounds and is roughly the size of a football. • Located in the upper right-hand part of the abdomen, behind the lower ribs. Gross Anatomy • The liver is divided) into four lobes: the right (the largest lobe), left , quadrate and caudate lobes. • Supplied with blood via the protal vein and hepatic artery. • Blood carried away by the hepatic vein. • It is connected to the diaphragm and abdomainal walls by five ligaments. • The liver is the only human organ that has the remarkable property of self- • Gall Bladder regeneration. If a part of the liver is – Muscular bag for the storage, removed, the remaining parts can concentration, acidification and grow back to its original size and delivery of bile to small shape. intestine Microscopic Anatomy • Hepatocyte—functional unit of the liver – Cuboidal cells – Arranged in plates lobules – Nutrient storage and release – Bile production and secretion – Plasma protein synthesis – Cholesterol Synthesis Microscopic Anatomy • Kuppfer cells – Phagocytic cells • Fat Storing Cells • Sinusoids – Fenestrated vessel – Wider than capillaries – Lined with endothelial cells – Blood flow • Branches of the hepatic artery • Branches of the Hepatic portal vein, central vein • Bile canaliculi Microscopic Anatomy Blood and Bile Flow in Opposite Directions • Blood Flow • Bile Flow • Deoxygenated blood from stomach or small intestine Hepatic • Bile produced in PortalVein venules sinusoids hepatocytes secreted into
    [Show full text]
  • GROSS ANATOMY Lecture Syllabus 2008
    GROSS ANATOMY Lecture Syllabus 2008 ANAT 6010 - Gross Anatomy Department of Neurobiology and Anatomy University of Utah School of Medicine David A. Morton K. Bo Foreman Kurt H. Albertine Andrew S. Weyrich Kimberly Moyle 1 GROSS ANATOMY (ANAT 6010) ORIENTATION, FALL 2008 Welcome to Human Gross Anatomy! Course Director David A. Morton, Ph.D. Offi ce: 223 Health Professions Education Building; Phone: 581-3385; Email: [email protected] Faculty • Kurt H. Albertine, Ph.D., (Assistant Dean for Faculty Administration) ([email protected]) • K. Bo Foreman, PT, Ph.D, (Gross and Neuro Anatomy Course Director in Dept. of Physical Therapy) (bo. [email protected]) • David A. Morton, Ph.D. (Gross Anatomy Course Director, School of Medicine) ([email protected]. edu) • Andrew S. Weyrich, Ph.D. (Professor of Human Molecular Biology and Genetics) (andrew.weyrich@hmbg. utah.edu) • Kerry D. Peterson, L.F.P. (Body Donor Program Director) Cadaver Laboratory staff Jordan Barker, Blake Dowdle, Christine Eckel, MS (Ph.D.), Nick Gibbons, Richard Homer, Heather Homer, Nick Livdahl, Kim Moyle, Neal Tolley, MS, Rick Webster Course Objectives The study of anatomy is akin to the study of language. Literally thousands of new words will be taught through- out the course. Success in anatomy comes from knowing the terminology, the three-dimensional visualization of the structure(s) and using that knowledge in solving problems. The discipline of anatomy is usually studied in a dual approach: • Regional approach - description of structures regionally
    [Show full text]
  • Arteriohepatic Dysplasia
    ANNALS OF CLINICAL AND LABORATORY SCIENCE, Vol. 14, No. 6 Copyright © 1984, Institute for Clinical Science, Inc. Arteriohepatic Dysplasia (Alagille’s Syndrome): A Common Cause of ConJugated Hyperbilirubinemia ELLEN KAHN, M.D.* and FREDRIC DAUM, M.D.f *Department of Laboratories and Department of Pediatrics, f Division of Pediatric Gastroenterology, Department of Pediatrics, North Shore University Hospital, Manhasset, NY 11030 Cornell University Medical College, New York, NY 10021 ABSTRACT Syndromatic paucity of interlobular bile ducts is a common cause of conjugated hyperbilirubinemia in children. The clinical presentation is not always obvious. Therefore, the liver biopsy may be a useful diagnostic tool in the definition of this entity. The hepatic and biliary morphology of five children with arteriohepatic dysplasia (Alagille’s syndrome) is described. Prior to diagnosis, four un­ derwent Kasai procedures after intraoperative cholangiograms failed to demonstrate patency of the extrahepatic bile ducts. In three patients, a focal proximal hypoplasia of the common hepatic duct was demonstrated. Hypoplasia of the gallbladder occurred in two patients. Hepatic features of seQuential liver biopsies obtained in the five patient^ were divided into early and late changes. From birth to four months of age, the pathology consisted of cholestasis and bile duct destruction. After four months of age, there was persistent cholestasis, paucity of interlobular bile ducts and portal fibrosis. The etiology of arteriohepatic dysplasia is unclear. The main pathoge­ nic mechanisms are discussed. It is felt that the syndromatic duct paucity represents an acquired primary ductal defect resulting from a genetically determined immune response to as yet undefined agent or agents. Introduction and may not be obvious in the newborn.
    [Show full text]