STRUCTURE and FUNCTIONS of DIGESTIVE SYSTEM The
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Embryology of Branchial Region
TRANSCRIPTIONS OF NARRATIONS FOR EMBRYOLOGY OF THE BRANCHIAL REGION Branchial Arch Development, slide 2 This is a very familiar picture - a median sagittal section of a four week embryo. I have actually done one thing correctly, I have eliminated the oropharyngeal membrane, which does disappear sometime during the fourth week of development. The cloacal membrane, as you know, doesn't disappear until the seventh week, and therefore it is still intact here, but unlabeled. But, I've labeled a couple of things not mentioned before. First of all, the most cranial part of the foregut, that is, the part that is cranial to the chest region, is called the pharynx. The part of the foregut in the chest region is called the esophagus; you probably knew that. And then, leading to the pharynx from the outside, is an ectodermal inpocketing, which is called the stomodeum. That originally led to the oropharyngeal membrane, but now that the oropharyngeal membrane is ruptured, the stomodeum is a pathway between the amniotic cavity and the lumen of the foregut. The stomodeum is going to become your oral cavity. Branchial Arch Development, slide 3 This is an actual picture of a four-week embryo. It's about 5mm crown-rump length. The stomodeum is labeled - that is the future oral cavity that leads to the pharynx through the ruptured oropharyngeal membrane. And I've also indicated these ridges separated by grooves that lie caudal to the stomodeum and cranial to the heart, which are called branchial arches. Now, if this is a four- week old embryo, clearly these things have developed during the fourth week, and I've never mentioned them before. -
Life Science Journal 2013;10(2) 479
Life Science Journal 2013;10(2) http://www.lifesciencesite.com Histological Observations on the Proventriculus and Duodenum of African Ostrich (Struthio Camelus) in Relation to Dietary Vitamin A. Fatimah A. Alhomaid1 and Hoda A. Ali2 1Dept. of Biology, Collage of Science and Arts, Qassim University, KSA 2Dept. of Nutrition and Food Science, Collage of Designs and Home Economy, Qassim University, KSA. Email: [email protected]; [email protected] Abstract: Research problem: The fine structure of the gut in different avian species in relation to dietary vitamins status have widely been studied with the exception of ostriches. Objectives: To study the histological structure of the African ostrich proventriculus and duodenum in relation to two levels of vitamin A (7500 and 9000) IU/kg diet using light microscope. Methods: Twenty male African ostriches with average age 65-67 weeks and apparently healthy were used. They were divided into two equal groups, the first one received diet adjusted to supply 7500 IU/kg diet vitamin A. The second group fed diet formulated to furnished 9000 IU/Kg diet vitamin A. Both diets were isonitrogenous and isocaloric. Body weight gain, feed intake and feed conversion rate were calculated. At the end of four weeks, pieces from the different parts of proventriculus and duodenum were taken for light microscopic examinations. Result: Body weight gain and feed conversion rate were improved in group received 9000IU of vitamin A comparable to group fed 7500IU. Histological structure of proventriculus of birds receiving 7500 IU/Kg vitamin A showing vascular congestion, thinning connective tissue and sloughing of the columnar epithelia lining the central collecting duct. -
Insect Digestion
INSECT DIGESTION Zoo 514 Dr. Reem Alajmi Insect digestive system The alimentary canal is concerned with digestion and absorption of food stuffs. Different parts of the gut are concerned with different aspects of these functions. In fluid feeding insects digestion begin before the food is ingested through the injection or regurgitation of enzymes on to the food . In general it occurs in the mid gut (most of the enzymes are produced). The enzymes break down the complex substances in the food into simple substances which can be absorbed and assimilated. Enzymes function optimally only within limited range of pH and temperature. Absorption is passive process in some cases , but in others active transport occurs. Absorption of water is important in terrestrial insects , rectum remove water from faeces. • Insects of different groups consume astonishing variety of foods, including watery xylem sap, vertebrate blood, dry wood, bacteria and algae and the internal tissues of other insects. • Types of mouth parts correlates with the diets of insect. Also gut structure and function affected by nutrient composition of the food eaten by insect. • Insects that take solid food typically have a wide, straight, short gut with strong musculature and obvious protection from abrasion (especially in the midgut, which has no cuticular lining). • These features are most obvious in solid-feeders with rapid throughput of food, as in many insects and plant-feeding caterpillars In contrast, insects feeding on blood, sap or nectar usually have long, narrow, convoluted guts to allow maximal contact with the liquid food; here, protection from abrasion is unnecessary. The most obvious gut specialization of liquid-feeders is a mechanism for removing excess water to concentrate nutrient substances prior to digestion, as seen in hemipterans. -
MINIREVIEW Posterior Gut Development in Drosophila: a Model System for Identifying Genes Controlling Epithelial Morphogen- Esis
Cell Research (1998), 8, 273-284 MINIREVIEW Posterior gut development in Drosophila: a model system for identifying genes controlling epithelial morphogen- esis LENGYEL JUDITH A* , XUE JUN LIU Department of Molecular, Cell and Developmental Biology University of California at Los Angeles, Los Angeles, CA USA, 90095-1606 USA ABSTRACT The posterior gut of the Drosophila embryo, consist- ing of hindgut and Malpighian tubules, provides a simple, well-defined system where it is possible to use a genetic approach to define components essential for epithelial mor- phogenesis. We review here the advantages of Drosophila as a model genetic organism, the morphogenesis of the ep- ithelial structures of the posterior gut, and what is known about the genetic requirements to form these structures. In overview, primordia are patterned by expression of hi- erarchies of transcription factors; this leads to localized expression of cell signaling molecules, and finally, to the least understood step: modulation of cell adhesion and cell shape. We describe approaches to identify additional genes that are required for morphogenesis of these simple epithelia, particularly those that might play a structural role by affecting cell adhesion and cell shape. Key words: Organogenesis, cell rearrangement, con- vergent extension, hindgut, Malpighian tubule. Advantages of Drosophila Work on Drosophila genetics began 90 years ago, when Thomas Hunt Morgan * Corresponding author: [email protected] Drosophila gut epithelial morphogenesis genes (who later received the Nobel Prize for his work) began studying inheritance in the fruit fly. At that time, the advantage of working with this small organism was that it reproduced rapidly in the laboratory, requiring only a simple growth medium, no special attention, and little expense. -
DIGESTIVE SYSTEM Generalized Insect Alimentary Tract the Digestive System Is Just a Tube Within a Surrounding Tube Called the Body
DIGESTIVE SYSTEM Generalized insect alimentary tract The digestive system is just a tube within a surrounding tube called the body. It starts with a mouth and ends with the anus. What goes on in between depends on the insect, its life stage and what it eats. The origin of the digestive tract. At the anterior pole of the embryo an indentation forms that will be the foregut or stomodeum. At the other end a similar thing occurs and the proctodeum or hindgut is formed. Both are lined by cuticle. They both are of ectodermal origin while the midgut is of mesodermal origin and is also called the mesenteron. This different origin of the midgut from the endoderm and not the ecotoderm probably explains why it is not lined with cuticle Anterior midgut invagination. In the bottom photo note the invagination starting forming the ventral furrow lumen (VF) MIDGUT FORMATION IN THE EMBRYO PMG in the above embryo shows the posterior midgut invagination cup where the posterior invagination shown in the drawing on the right will take place. Photo of Drosophila embryo. Hindgut invagination DIGESTIVE SYSTEM The digestive tract not only aids in obtaining, processing and digesting food molecules - It is the largest endocrine tissue in both humans and insects. The digestive system is involved in: 1. Obtaining food 2. Mechanically breaking it down into smaller particles that facilitate digestive enzymes acting on them 3. Enzymatic breakdown of larger food molecules into molecules that can pass through the digestive tract (midgut) and enter the hemolymph 4. Produces molecules or MESSENGERS (eg. -
Histogenesis of the Proventricular Submucosal Gland of the Chick As Revealed by Light and Electron Microscopy Dale S
HISTOGENESIS OF THE PROVENTRICULAR SUBMUCOSAL GLAND OF THE CHICK AS REVEALED BY LIGHT AND ELECTRON MICROSCOPY DALE S. THOMSON Malone College, Canton, Ohio ABSTRACT The development of the submucosal tubuloalveolar glands of the proventriculus was studied with both light and electron microscopes, with special reference given to the 13-18-day period. Beginning as an invagination in the stratified columnar epithelium lining the lumen of the proventriculus, the simple tubular gland, by repeated bifurcation of the invaginated portion, by sloughing of the superficial cells, and by remodeling of the residual basal cells from columnar to cuboidal, becomes a compound tubuloalveolar gland composed of numerous secretory units. Concomitant with the gross cellular changes, ultra- structural changes in the intercellular membranes are evident. By day 4 after hatching, the cells forming the secretory units appear to be functional. INTRODUCTION The avian stomach is peculiar in that it consists of two morphologically and physiologically distinct parts: the glandular portion, or proventriculus, and the muscular portion, or gizzard. The proventriculus is a relatively thick-walled structure located at the distal end of the oesophagus and containing both simple mucous-secreting glands and compound submucosal tubuloalveolar glands. The gizzard is a thick muscular bulb, the mucosa of which contains simple glandular cells which secrete a tough, horny layer. The proventriculus has been described by Cazin (1886, 1887), Zietschmann (1908), Calhoun (1933, 1954), Batt (1924), and Bradley and Graham (1950). Aitken (1958) and Toner (1963) further amplified the literature with specific reference to the compound submucosal glands. Sjogren (1941) and Hibbard (1942) described the embryonic development of the submucosal glands. -
Gastrointestinal Tract Morphometrics and Content of Commercial and Indigenous Chicken Breeds with Differing Ranging Profiles
animals Article Gastrointestinal Tract Morphometrics and Content of Commercial and Indigenous Chicken Breeds with Differing Ranging Profiles Joanna Marchewka 1,*, Patryk Sztandarski 1 , Zaneta˙ Zdanowska-S ˛asiadek 1, Dobrochna Adamek-Urba ´nska 2 , Krzysztof Damaziak 3, Franciszek Wojciechowski 1, Anja B. Riber 4 and Stefan Gunnarsson 5 1 Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrz˛ebiec, 05-552 Magdalenka, Poland; [email protected] (P.S.); [email protected] (Z.Z.-S.);˙ [email protected] (F.W.) 2 Department of Ichthyology and Biotechnology in Aquaculture, Institute of Animal Science, Warsaw University of Life Sciences, 02-786 Warsaw, Poland; [email protected] 3 Department of Animal Breeding, Faculty of Animal Breeding, Bioengineering and Conservation, Institute of Animal Science, Warsaw University of Life Sciences, 02-786 Warsaw, Poland; [email protected] 4 Department of Animal Science, Aarhus University, DK-8830 Aarhus, Tjele, Denmark; [email protected] 5 Department of Animal Environment and Health, Swedish University of Agricultural Sciences (SLU), S-532 23 Skara, Sweden; [email protected] * Correspondence: [email protected] Simple Summary: Differences in the range use by poultry exist on the individual or breed level, even if equal opportunity of outdoor access is provided. Birds reared with access to the pasture consume some of Citation: Marchewka, J.; Sztandarski, the material found outdoors, such as plants, insects, and stones. The frequency of outdoor range use may P.; Zdanowska-S ˛asiadek, Z.;˙ Adamek-Urba´nska,D.; Damaziak, K.; be associated with the ingested material and the development of the bird gut. -
Elixir Journal
45637 Ganesh Elumalai and Jenefa Princess / Elixir Embryology 103 (2017) 45637-45640 Available online at www.elixirpublishers.com (Elixir International Journal) Embryology Elixir Embryology 103 (2017) 45637-45640 “CLOACAL MEMBRANE ANOMALIES” EMBRYOLOGICAL BASIS AND ITS CLINICAL IMPORTANCE Ganesh Elumalai and Jenefa Princess Department of Embryology, College of Medicine, Texila American University, South America. ARTICLE INFO ABSTRACT Article history: Cloacal malformation is a rare but important anomaly. The cloacal anomaly is Received: 1 January 2017; characterised by the persistence of a common channel draining the urinary, genital and Received in revised form: alimentary tracts through a single orifice. It results from abnormal compartmentalization 1 February 2017; of features that are normal in the primitive female embryo. Abnormal embryology and Accepted: 10 February 2017; cloacal anatomy are described in detail. Cloacal abnormalities are usually diagnosed promptly in the neonatal period. Keywords © 2017 Elixir All rights reserved. Cloacal membrane, Uro-rectal septum, Extrophy of the cloaca, Recto-urinary fistulas, Anal agenesis, Rectal atresia. Introduction dilate them to make an anus.. Initial management focuses on Abnormal cloacal development takes place when rectum, anatomic remodelling of the urinary and gastrointestinal vagina and lower urinary tract fuse into a single common system to achieve continence. Improved paediatric channel. Persistent cloaca is a most severe malformation of management strategies have increased the patient survival into cloacal anomalies in girls and is associated with complex adult life. In order to provide appropriate advice, clinicians pelvic malformations. The abnormality of these structures who are undertaking life-long management of adolescent and varies from bladder neck to just beneath the perineal skin. -
A STUDY of ORIGIN, COURSE and VARIATIONS of INFERIOR MESENTERIC ARTERY and ITS BRANCHES Deepa S Ashalatha P R Original Research
Original Research Paper Volume - 7 | Issue - 6 | June - 2017 | ISSN - 2249-555X | IF : 4.894 | IC Value : 79.96 Anatomy A STUDY OF ORIGIN, COURSE AND VARIATIONS OF INFERIOR MESENTERIC ARTERY AND ITS BRANCHES Senior Resident, Department of Anatomy, Government medical college Calicut, Kerala Deepa S 673008 Additional professor, Department of Anatomy, Government medical college, Calicut, Ashalatha P R Kerala 673008 ABSTRACT Knowledge of inferior mesenteric arteries is essential for surgical and radiological procedures. AIM: To study the origin, course, branches and variations of inferior mesenteric arteries. MATERIALS AND METHODS: 50 human cadavers by dissection method. RESULT: Inferior mesenteric artery arose from aorta in all 50 cases. Left colic artery arose from IMA in all 50 cases. Sigmoid arteries arose either directly from IMA or as sigmoid trunk in common with LCA or separately from IMA KEYWORDS : superior mesenteric artery, inferior mesenteric artery, aorta. INTRODUCTION 3. Variations in the branching pattern The mesenteric arterial supply is a combination of rich collateral 4. Presence of any uncommon branches networks and commonly encountered variant anatomy. The effect of normal and variant anatomy has implications on pathology, treatment MATERIALS AND METHODS choices, and planning interventions. A review of anatomic variants The material examined consisted of 50 formalin fixed cadavers will assist in understanding the implications of abnormal anatomy on obtained from the Department of Anatomy, Government Medical treatment for diseases associated with the mesentery. College, Kozhikode. The abdomen was opened by roof top incision. The mesentery of the small intestine in the infracolic compartment was Differences arising during several developmental stages in the exposed by turning the transverse colon and its mesentery upwards. -
Avian Digestion
4/5/2012 Avian digestion I. Introduction A. Shapes II. Taxonomy of food habits B. Grinding Function A. Herbivores C. Crop Milk B. Carnivores D. Other Functions A wonderful bird is the pelican, III. Mouth and Pharynx V. Stomach His bill will hold more than his belly can. A. Bill A. Proventriculus He can take in his beak B. Palate B. Ventriculus Food enough for a week, C. Tongue VI. Small Intestine But I'm damned if I see how the hell he D. Salivary Glands A. Duodenum can. IV. Esophagus and Crop B. Function A. Storage --Dixon Lanier Merritt (1879-?) The Pelican (1910) I. Introduction Digestive system needs to be as light as possible High metabolic rates require large extremely efficient amounts of fuel warbler might eat 80 percent of its body weight in a day! 1 4/5/2012 Loss of teeth and minimum jaw musculature Problem for birds – need to keep low body weight Thus, little fat storage need to locate, ingest, digest food as quickly and efficiently as possible Stellar’s Sea Eagle Major components of avian digestive system II. Taxonomy of food habits • oral cavity Many birds are generalists but many are also specialists • pharynx • esophagus (+ crop) Specializations are evident through the entire alimentary • stomach (proventriculus, canal. ventriculus) • small intestine • large intestine • cloaca 2 4/5/2012 As a group birds consume about any kind of food A. Herbivores ants nectar Granivores buds pollen Frugivores crustaceans roots Nectivores fish sap Folivores fruit snails grass wax insects etc. leaves B. Carnivores III. Mouth and Pharynx Raptors A. -
Embryology and Teratology in the Curricula of Healthcare Courses
ANATOMICAL EDUCATION Eur. J. Anat. 21 (1): 77-91 (2017) Embryology and Teratology in the Curricula of Healthcare Courses Bernard J. Moxham 1, Hana Brichova 2, Elpida Emmanouil-Nikoloussi 3, Andy R.M. Chirculescu 4 1Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, Wales, United Kingdom and Department of Anatomy, St. George’s University, St George, Grenada, 2First Faculty of Medicine, Institute of Histology and Embryology, Charles University Prague, Albertov 4, 128 01 Prague 2, Czech Republic and Second Medical Facul- ty, Institute of Histology and Embryology, Charles University Prague, V Úvalu 84, 150 00 Prague 5 , Czech Republic, 3The School of Medicine, European University Cyprus, 6 Diogenous str, 2404 Engomi, P.O.Box 22006, 1516 Nicosia, Cyprus , 4Department of Morphological Sciences, Division of Anatomy, Faculty of Medicine, C. Davila University, Bucharest, Romania SUMMARY Key words: Anatomy – Embryology – Education – Syllabus – Medical – Dental – Healthcare Significant changes are occurring worldwide in courses for healthcare studies, including medicine INTRODUCTION and dentistry. Critical evaluation of the place, tim- ing, and content of components that can be collec- Embryology is a sub-discipline of developmental tively grouped as the anatomical sciences has biology that relates to life before birth. Teratology however yet to be adequately undertaken. Surveys (τέρατος (teratos) meaning ‘monster’ or ‘marvel’) of teaching hours for embryology in US and UK relates to abnormal development and congenital medical courses clearly demonstrate that a dra- abnormalities (i.e. morphofunctional impairments). matic decline in the importance of the subject is in Embryological studies are concerned essentially progress, in terms of both a decrease in the num- with the laws and mechanisms associated with ber of hours allocated within the medical course normal development (ontogenesis) from the stage and in relation to changes in pedagogic methodol- of the ovum until parturition and the end of intra- ogies. -
An Emerging Exotic Disease of Parrots in Australia AVIAN, UNUSUAL & EXOTIC
avj_109.fm Page 119 Thursday, February 15, 2007 9:35 AM AVIAN, UNUSUAL & EXOTIC Blackwell Publishing Asia CASE REPORT CORE Metadata, citation and similar papers at core.ac.uk Provided by University of QueenslandProventricular eSpace dilatation disease: an emerging exotic disease of parrots in Australia AVIAN, UNUSUAL & EXOTIC RJT DONELEY,a RI MILLERb and TE FANNINGa syndrome of weight loss associated with regurgitation and the Proventricular dilatation disease is a viral disease seen as a passage of undigested food in the faeces, other clinical signs also segmental neuropathy in parrots. It has always been believed include ataxia, abnormal head movements, progressive paresis, to be a disease exotic to Australia, with the only reported case proprioceptive deficits, anorexia, lethargy and, occasionally, being a legally imported Green Wing Macaw (Ara chloroptera) 3 in 1993. This paper reports a cluster of cases seen in south- sudden death. K Rosenthal (personal communication) and D east Queensland in 2005 to 2006. Clinical signs, autopsy Monks (personal communication) consider that, in contrast to findings and histopathological findings are described. No other species, polyuria and polydipsia are frequently seen in Gray pattern or common source for these cases could be identified. parrots (Psittacus erithacus erithacus) affected with PDD. The implications for Australian aviculture and avifauna are discussed. A variety of aetiological agents have been proposed, including paramyxovirus, togavirus, adenovirus, coronavirus,4 and Eastern Key words: proventricular dilatation disease, psittacines, parrots, exotic disease Equine Encephalitis virus. Other suggested aetiologies included Aust Vet J 2007;85:119–123 doi: 10.1111/j.1751-0813.2007.00109.x immune-mediated reactions to an unknown viral agent, how- ever, no consistent viral isolation or serological findings have AST Aspartate aminotransferase confirmed the involvement of any one virus.