Infobox Embryology Name Endoderm Latin GraySubject 6 GrayPage 49 Image Endoderm2.png Caption Organs derived from endoderm. Image2 Gray10.png Caption2 Blastodermic vesicle of Vespertilio murinus . Endoderm labeled as entoderm . System CarnegieStage Days 16 Precursor hypoblast GivesRiseTo splanchnopleure MeshName Endoderm MeshNumber A16.254.425.407 DorlandsPre DorlandsSuf Endoderm is one of the three primary germ cell layers in the very early embryo. The other two layers are the ectoderm outside layer and mesoderm middle layer , with the endoderm as the intermost layer. ref Langman s Medical Embryology, 11th edition. 2010. ref Cells migrating inward along the archenteron form the inner layer of the gastrula , which develops into the endoderm. Citation needed date January 2011 The endoderm consists at first of flattened cells, which subsequently become columnar. It forms the epithelial lining of multiple systems. Citation needed date January 2011 Production The following chart shows the products produced by the endoderm. class wikitable Layer Category System General ref The General category denotes that all or most of the animal s containing this layer produce the adjacent product. ref Gastrointestinal tract . the entire alimentary canal except part of the mouth , pharynx and the terminal ... cite journal author Zaret KS title Hepatocyte differentiation from the endoderm and beyond journal ... The Endoderm has differentiated into distinguishable organs as early as 5 weeks of embryonic development ... Organogenesis Endodermal sinus tumor References reflist wiktionary endoderm Embryology Human cell types derived primarily from endoderm Gray s Category Developmental biology Category Embryology Category Gastrulation ar bg ca Endoderma cs Entoderm da Endoderm de Entoderm es ... nl Endoderm pl Entoderma pt Endoderme ru sr fi Endodermi sv Endoderm th tr Endoderm uk zh ... more details
Enterocoely adjective forms enterocoelic or enterocoelous is a process by which some animal embryonic development embryos develop . In enterocoely, a mesoderm is formed in a developing embryo , in which the coelom forms from pouches pinched off of the digestive tract also known as the embryonic gut, or archenteron . This type of coelom formation occurs in deuterostome animals, which for this reason are also known as enterocoelomates . Enterocoelous development begins once the embryo reaches the gastrula phase of development. At this point, there are two layers of cells the ectoderm outermost and the endoderm innermost layers. The mesoderm middle layer begins to form as two pockets of tissue one above the endoderm, and one below are formed via folding of the endoderm. These pockets begin to grow larger, and as they do so, they extend towards each other. When the two pockets of cells meet, the mesoderm is formed a complete layer of tissue right in between the endoderm and ectoderm layers. This then leads to the formation of a coelom . Enterocoelous development is the stage of embryological development of deuterostomes in which the coelom forms. The stage starts with the gastrula as the archenteron forms, pockets of migrating cells also form, creating another layer between the endoderm and ectoderm , the mesoderm . These pockets gradually expand to form the coelom. In protostomes, the body cavity is formed by schizocoely . developmental biology stub See also Schizocoely External links http www.mhhe.com biosci pae glossaryd.html PAE Virtual Glossary Category Embryology de Enterocoelie es Enterocelia fr Ent roc lie it Enterocelia pt Celoma enteroc lico ... more details
Unreferenced stub auto yes date December 2009 Diploblasty is a condition of the blastula in which there are two primary germ layer s the ectoderm and endoderm . Diploblastic organisms are organisms which develop from such a blastula, and include cnidaria and ctenophora , formerly grouped together in the phylum Coelenterata, but later understanding of their differences resulted in them being placed in separate phyla. The endoderm allows them to develop true Biological tissue tissue . This includes tissue associated with the gut and associated glands. The ectoderm on the other hand gives rise to the epidermis, the nervous tissue, and if present, nephridia. Simpler animals, such as sea sponges , have one germ layer and lack true tissue organisation. All the more complex animals from flat worms to humans are triploblastic with three germ layers a mesoderm as well as ectoderm and endoderm . The mesoderm allows them to develop true Organ anatomy organs . See also Triploblasty Category Developmental biology Developmental biology stub ca Diplobl stia es Dibl stico fa fr Diploblastique nn Diploblastiske dyr pl Dwuwarstwowce pt Diplobl stico ru sv Diploblastica ... more details
two layers, called the ectoderm and endoderm . Therefore, they are diploblastic . Animals with symmetry ... s biological tissue tissues and organ anatomy organ s through a process called organogenesis . Endoderm main Endoderm The endoderm is one of the germ layers formed during animal embryogenesis. Cells migrating inward along the archenteron form the inner layer of the gastrula , which develops into the endoderm . Initially, the endoderm consists of flattened cells, which subsequently become columnar ... inward to form the endoderm form an additional layer between the endoderm and the ectoderm ... layer s. Production File Germ layers.png thumb 575px The endoderm produces tissue within the lung s, thyroid ... Germ Layer Category Product Endoderm General ref The General category denotes that all or most of the animal ... General Respiratory tract Endoderm General Endocrine glands and organs liver and pancreas Mesoderm ... of the Endoderm and Mesoderm Embryology Human cell types derived primarily from mesoderm ... more details
An exocrine pancreas cell is a pancreatic cell that produces enzymes that are secreted into the small intestine . These enzymes help digest food as it passes through the gastrointestinal tract . Main article Exocrine pancreas . External links http www.cancer.gov Templates db alpha.aspx?CdrID 270856 Exocrine pancreas cell entry in the public domain NCI Dictionary of Cancer Terms NCI cancer dict Category Pancreas anatomy Human cell types derived primarily from endoderm ... more details
In the Embryogenesis development of Vertebrate vertebrate animals , the prechordal plate is a uniquely thickened portion of the endoderm that is in contact with ectoderm immediately Anatomical terms of location Directional terms rostral to the cephalic tip of the notochord . ref http www.mondofacto.com facts dictionary?prechordal plate Mondofacto Online Medical Dictionary ref It is the most likely origin of the rostral cranial mesoderm. ref Seifert, R et al. J Anat 1993 183 75 89 ref References Reflist Category Developmental biology ... more details
the endoderm red . Image Teratoma 2 low mag.jpg thumb right Micrograph of a teratoma , a tumour that characteristically ... immature cartilage left upper corner of image , endoderm gastrointestinal glands center bottom .... Huxley Huxley in 1871 and ectoderm and endoderm by Ray Lankester Lankester in 1873. Among animal s, sea ... animals, Cnidaria and Ctenophora , show an increase in complexity, having two germ layers, the endoderm ..., dives down into it, and forms a new layer, called the endoderm , pushing the hypoblast out of the way ... . The top layer is now called the ectoderm . citation needed date January 2011 Endoderm Image Endoderm2.png thumb 200px The endoderm produces tissue within the lung s, thyroid , and pancreas . main Endoderm The endoderm is one of the germ layers formed during animal embryogenesis. Cells migrating inward along the archenteron form the inner layer of the gastrula, which develops into the endoderm . The endoderm consists at first of flattened cells, which subsequently become columnar. It forms the epithelial .... The endoderm forms the stomach, the colon, the liver, the pancreas, the urinary bladder, the lining ... layer between the endoderm and the ectoderm . The formation of a mesoderm led to the development ... more details
Image Germ layers.png thumb 400px The endoderm produces tissue within the lung s, thyroid , and pancreas . The mesoderm aids in the production of cardiac muscle , skeletal muscle , smooth muscle , tissues within the kidney s, and red blood cell s. The ectoderm produces tissues within the Epidermis skin epidermis and aids in the formation of neuron s within the brain, and melanocytes . In embryogenesis animal development , organogenesis organo genesis, compound of the Greek language Greek words that with which one works , ref http www.etymonline.com index.php?term organ Definition of organ from the Online Etymology Dictionary ref and origin, creation, generation ref http www.etymonline.com index.php?term genesis Definition of genesis from the Online Etymology Dictionary ref is the process by which the ectoderm , endoderm , and mesoderm develop into the internal organ s of the organism. Internal organs initiate development in humans within the 3rd to 8th weeks in utero. The germ layer s in organogenesis differ by three processes folds, splits, and condensation. Developing early during this stage in chordate animals are the neural tube and notochord . Vertebrate animals all differentiate from the gastrula the same way. Vertebrates develop a neural crest that differentiates into many structures, including some bones, muscles, and components of the peripheral nervous system . The coelom of the body forms from a split of the mesoderm along the somite axis . citation needed date January 2011 In plants, organogenesis can occur from totipotent callus cells. clear See also wiktionary organogenesis Ectoderm Embryogenesis Endoderm Eye development Germ layer Germ line development Heart development Histogenesis Limb development Mesoderm Morphogenesis References reflist Embryology Germ layer Category Developmental biology Category Embryology Category Greek loanwords ca Organog nesi de Organogenese es Organog nesis fa id Organogenesis is L ff ramyndun it Organogenesi ... more details
Infobox Embryology Name PAGENAME Latin mesenchyma splanchnopleurale GraySubject 6 GrayPage 50 Image Gray16.png Caption A series of transverse sections through an embryo of the dog. After Bonnet. Section I is the most anterior. In V the neural plate is spread out nearly flat. The series shows the uprising of the neural folds to form the neural canal. a. Aort . c. Intermediate cell mass. ect. Ectoderm. ent. Entoderm. h, h. Rudiments of endothelial heart tubes. In III, IV, and V the scattered cells represented between the endoderm and splanchnic layer of mesoderm are the vasoformative cells which give origin in front, according to Bonnet, to the heart tubes, h l.p. Lateral plate still undivided in I, II, and III in IV and V split into somatic sm and splanchnic sp layers of mesoderm. mes. Mesoderm. p. Pericardium. so. Primitive segment. Image2 Gray457.png Caption2 Transverse section through the region of the heart in a rabbit embryo of nine days. X 80. K lliker. j, j. Jugular veins. ao. Aorta. ph. Pharynx. som. Somatopleure. bl. Proamnion. ect. Ectoderm. ent. Entoderm. p. Pericardium. spl. Splanchnopleure. ah. Outer wall of heart. ih. Endothelial lining of heart. . Septum between heart tubes. System CarnegieStage 9 Days Precursor lateral plate mesoderm , endoderm GivesRiseTo mesenchyme MeshName MeshNumber Code Terminologia Embryologica TE E4.0.4.1.0.0.4 In the anatomy of an embryo , the splanchnopleuric mesenchyme is a structure created during embryogenesis when the lateral mesoderm splits into two layers. The inner or splanchnic layer adheres to the endoderm , and with it forms the splanchnopleure. See also somatopleure mesenchyme External links EmbryologyUNC digest 022 EmbryologyUNC digest 023 http science.kennesaw.edu rmatson Biol 203350 Somatopleure.html Overview at Kennesaw State University developmental biology stub Gray s Embryology Category Embryology fr Splanchnopleure pt Esplancnopleura ... more details
Expand Spanish date July 2010 Hipoblasto Infobox Embryology Name Hypoblast Latin hypoblastus GraySubject GrayPage Image Gray21.png Caption Section through the embryo. Hypoblast visible but not labeled. Image2 Cell differentiation gastrula.PNG Caption2 D points to the hypoblast. System CarnegieStage Days 8 Precursor inner cell mass GivesRiseTo endoderm MeshName MeshNumber Code Terminologia Embryologica TE E6.0.1.1.3.0.4 The hypoblast is a tissue type that forms from the inner cell mass . ref http embryology.med.unsw.edu.au Notes Index H.htm UNSW Embryology Glossary H Bot generated title ref It lies beneath the epiblast and consists of small cuboidal cells. ref Moore, K. L., and Persaud, T. V. N. 2003 . The Developing Human Clinically Oriented Embryology . 7th Ed. Philadelphia Elsevier. ISBN 0 7216 9412 8. ref Extraembryonic endoderm including Yolk sac is derived from hypoblast. Its absence results in multiple primitive streak s in chicken embryos. ref name perea gomez cite journal doi 10.1016 S1534 5807 02 00321 0 author Perea Gomez A, Vella FD, Shawlot W, Oulad Abdelghani M, Chazaud C, Meno C, Pfister V, Chen L, Robertson E, Hamada H, Behringer RR, Ang SL. title Nodal antagonists in the anterior visceral endoderm prevent the formation of multiple primitive streaks journal Dev Cell. volume 3 pages 745 56. year 2002 pmid 12431380 issue 5 ref References Reflist External links http www.embryology.ch allemand iperiodembry carnegie02.html http www.med.umich.edu lrc coursepages M1 embryology embryo 04secondweek.htm http isc.temple.edu marino embryology EMBII97 sld005.htm Embryology Category Embryology anatomy stub de Hypoblast es Hipoblasto ru zh ... more details
Unreferenced stub auto yes date December 2009 Infobox Anatomy Name PAGENAME Latin endocrinocytus S GraySubject GrayPage Image Caption Image2 Caption2 Precursor System Artery Vein Nerve Lymph MeshName MeshNumber Code Terminologia Histologica TH H3.04.02.0.00037 S cells are cells which release secretin , found in the jejunum and duodenum . They are stimulated by a drop in pH to 4 or below in the small intestine s lumen. The released secretin will increase the secretion of HCO sub 3 sub sup sup into the lumen, via the pancreas . S cells are also one of the main producers of cyclosamatin . Gastrointestinal physiology Human cell types derived primarily from endoderm DEFAULTSORT S Cell Category Human cells Category Digestive system Cell biology stub ru S sv S cell ... more details
Unreferenced section date December 2007 Two types of pneumocytes also named pneumonocyte contribute to the maintenance of the alveoli of the lungs Type I pneumocyte s and Type II pneumocyte s. These cells function to aid in gas exchange, secretion of pulmonary surfactant , and self regeneration See also Dust cell External links KansasHistology resp resp17 BUHistology 13905loa http www.meddean.luc.edu lumen bbs p ppi10.html Electron micrograph at luc.edu Lower respiratory system anatomy Human cell types derived primarily from endoderm Category Lung anatomy Category Human cells cell biology stub respiratory stub cs Pneumocyt fr Pneumocyte gl Pneumocito id Pneumosit it Pneumocita kk pl Pneumocyt pt Pneum cito ru ... more details
Infobox embryology Name PAGENAME Latin blastocystis trilaminaris GraySubject GrayPage Image Caption Image2 Caption2 MeshName MeshNumber Code Terminologia Embryologica TE E6.0.1.1.4.0.1 A trilaminar embryo or trilaminary blastoderm , or trilaminar germ disk is an early stage in the development of triploblastic organisms, which include humans and many other animals. It is an embryo which exists as three different germ layer s the ectoderm , the mesoderm and the endoderm . These layers are arranged on top of each other like a stack of paper, giving rise to the name trilaminar , or three layered . It arises early in the third week, after gastrulation . External links eMedicineDictionary trilaminar blastoderm EmbryologySwiss hdisqueembry triderm01 EmbryologyUNSW Notes week3 4 http staff.um.edu.mt acus1 Gasrtrulation.htm Overview at edu.mt Embryology Category Embryology developmental biology stub ... more details
Sinus tubercle is the proliferation of endoderm induced by the paramesonephric ducts . The uterovaginal primoridium , which is a fusion of the caudal ends of paramesonephric ducts contacts the dorsal wall of the urogenital sinus and, induces the formation of the sinus tubercle. This occurs in both sexes In the female the mesonephric duct loses all association with the gonad and, disappears. It gives rise to the sino vaginal bulb s and, when it later becomes solid it is referred to as the vaginal plate . It likewise gives rise to the hymen , which eventually breaks down. In the males, the sinus tubercle gives rise to the seminal colliculus . References Moore Persaud, Medical embryology 2003 Development of urinary and reproductive systems Category Developmental biology Category Embryology ... more details
unreferenced date September 2009 The stomochord is a flexible, hollow tube found in hemichordates . Stomochords were initially considered a variant of a primitive notochord , but are now recognized to not share histological composition to that of the notochord found in chordates. citation needed date September 2009 Stomochords arise in embryonic development as an outpocketing from the roof of the embryonic gut anterior to the pharynx. In adults, they extend dorsally from the pharynx into the probiscis, and serve to communicate with the oral cavity. Their walls are composed primarily of epithelial cells , but ciliated and glandular cells are also present. citation needed date September 2009 div class metadata plainlinks stub style clear both background transparent This article is a Wikipedia Stub stub . You can help Wikipedia by fullurl FULLPAGENAME action edit expanding it . div Category Endoderm Category Histology cs Stomochord ... more details
Infobox Anatomy Name Cholecystocyte Latin cholecystocytus GraySubject GrayPage Image Caption Image2 Caption2 Precursor System Artery Vein Nerve Lymph MeshName MeshNumber Code Terminologia Histologica TH H3.04.06.0.00006 A cholecystocyte is an epithelial cell found in the gallbladder . ref Cite journal last1 Maurer first1 KJ. last2 Carey first2 MC. last3 Fox first3 JG. title Roles of infection, inflammation, and the immune system in cholesterol gallstone formation. journal Gastroenterology volume 136 issue 2 pages 425 40 month Feb year 2009 doi 10.1053 j.gastro.2008.12.031 PMID 19109959 ref References reflist Accessory digestive glands Human cell types derived primarily from endoderm anatomy stub Category Epithelial cells Category Hepatology Category Human cells ... more details
Infobox Embryology Name Ectoderm Latin GraySubject 6 GrayPage 48 Image Ectoderm.png Caption Organs derived from ectoderm. Image2 Gray11.png Caption2 Section through embryonic disk of Vespertilio murinus . System CarnegieStage Days 16 Precursor GivesRiseTo MeshName Ectoderm MeshNumber A16.254.425.273 DorlandsPre DorlandsSuf The ectoderm is one of the three primary germ cell layers in the very early embryo. The other two layers are the mesoderm middle layer and endoderm most proximal layer , with the ectoderm as the most exterior or distal layer. ref Langman s Medical Embryology, 11th edition. 2010. ref It emerges first and forms from the outer layer of germ cells. Generally speaking, the ectoderm differentiates to form the nervous system spine, peripheral nerves and brain , ref http www.bioethics.gov reports stemcell glossary.html ref ref name simple http simple.wikipedia.7val.com wiki Mate ref tooth Tooth enamel enamel and the Epidermis skin epidermis the outer part of integumentary system integument . It also forms the lining of mouth, anus, nostrils, sweat glands, hair and nails. ref name simple In vertebrate s, the ectoderm has three parts external ectoderm also known as surface ectoderm , the neural crest , and neural tube . The latter two are known as neuroectoderm . Image Gray32.png thumb left Section through ovum imbedded in the uterine decidua clear See also Ectoderm specification Coelom Embryology Endoderm Gastrulation Mesoderm References Reflist Embryology Human cell types derived primarily from ectoderm Category Developmental biology Category Embryology Category Gastrulation developmental biology stub ar bg ca Ectoderma cs Ektoderm de Ektoderm es Ectodermo eo Ektodermo fr Ectoderme io Ektodermo it Ectoderma ht Ektod m hu Ektoderma nl Ectoderm no Ektoderm pl Ektoderma pt Ectoderme ro Ectoderm ru sk Ektoderma sr fi Ektodermi sv Ektoderm th tr Ektoderm uk zh ... more details
The primitive gut that forms during gastrulation in the developing blastula is known as the archenteron . It develops into the digestive tract of an animal. Formation of the Archenteron in Sea Urchins See Gastrulation . As primary mesenchyme cells detach from the vegetal pole in the gastrula and enter the fluid filled cavity in the center the blastocoel , the remaining cells at the vegetal pole flatten to form a vegetal plate . This buckles inwards towards the blastocoel in a process called invagination . The cells continue to be rearranged until the shallow dip formed by invagination transforms into a deeper, narrower pouch formed by the gastrula s endoderm . This narrowing and lengthening of the archenteron is driven by convergent extension . The open end of the archenteron is called the blastopore . File Protovsdeuterostomes.svg right thumb The Archenteron is labeled as the digestive tube The filopodia thin fibers formed by the mesenchyme cells found in a late gastrula contract to drag the tip of the archenteron across the blastocoel. The endoderm of the archenteron will fuse with the ectoderm of the blastocoel wall. At this point gastrulation is complete, and the gastrula has a functional digestive tube. The indentation that is actually formed is called the lip of the blastopore in amphibian s and fish , and the primitive streak in bird s and mammal s. Each is controlled by the dorsal blastopore , and primitive node also known as Hensen s node , respectively. During Gastrulation , the Archenteron develops into the digestive tube, with the blastopore developing into either the mouth Protostome or the anus Deuterostome External links http chsweb.lr.k12.nj.us mstanley outlines animals antax image51.gif Diagram developmental biology stub Embryology Category Developmental biology ca Arqu nteron cs Prvost evo de Archenteron es Arqu nteron fr Archent ron it Archenteron ja pl Prajelito pt Arqu ntero zh ... more details
Infobox Embryology Name PAGENAME Latin nodus primitivus GraySubject 6 GrayPage 47 Image Caption Image2 Caption2 System CarnegieStage Days 17 Precursor GivesRiseTo MeshName MeshNumber DorlandsPre k 04 DorlandsSuf 12471954 The primitive knot or primitive node is the organizer for gastrulation in vertebrates. Diversity In bird s it is known as Hensen s node , and is named after its discoverer Victor Hensen . In amphibian s, it is known as Spemann s organizer , and is named after Hans Spemann who, with Mangold, first identified the organizer in 1924. ref name pmid17563072 cite journal author Garcia Fern ndez J, D Aniello S, Escriv H title Organizing chordates with an organizer journal Bioessays volume 29 issue 7 pages 619 24 year 2007 pmid 17563072 doi 10.1002 bies.20596 ref Development The primitive knot starts as a regional knot of cells that forms on the blastodisc immediately anterior to where the outer layer of cells will begin to migrate inwards an area known as the primitive streak . Posterior to the node is the primitive pit, where the cells of the epiblast the upper layer of embryonic cells initially begin to invaginate. This invagination expands posteriorly into the primitive groove as the cells layers continue to move into the space between the embryonic cells and the yolk. This differentiates the embryo into the germ layer s endoderm, mesoderm, and ectoderm. The primitive knot migrates posteriorly as gastrulation proceeds, eventually being absorbed into the tail bud. The Default Model The cells of the primitive node secrete many cellular signals essential for neural differentiation. After gastrulation the developing embryo is divided into ectoderm, mesoderm, and endoderm. The ectoderm gives rise to epithelial and neural tissue, with neural tissue being the default cell fate. Bone morphogenetic proteins BMPs suppress neural differentiation and promote epithelial growth. Therefore, the primitive node the dorsal lip of the blastopore secretes BMP antagonists, ... more details
Infobox Embryology Name PAGENAME Latin membrana cloacalis GraySubject 6 GrayPage 47 Image Gray991.png Caption Tail end of human embryo from fifteen to eighteen days old. Image2 Caption2 System Days 15 CarnegieStage 7 Precursor caudal end of the primitive streak GivesRiseTo MeshName MeshNumber Code Terminologia Embryologica TE E5.4.0.0.0.0.15 The cloacal membrane is the membrane that covers the embryonic cloaca when still in the development of the urinary and reproductive organs . It is formed by ectoderm and endoderm coming into contact with each other. ref name urlEndoderm Developmental Biology NCBI Bookshelf cite web url http www.ncbi.nlm.nih.gov bookshelf br.fcgi?book dbio&part A3745 title Endoderm Developmental Biology NCBI Bookshelf format work accessdate ref After separation of the cloaca into the urogenital and anal parts, the cloacal membrane, in turn, is separated into a urogenital membrane and an anal membrane . It has been suggested that developmental errors may be associated with enlarged clitorises . ref name pmid19944238 cite journal author van der Putte SC title Penislike clitorises with megalourethras in nonvirilized female fetuses and a newborn. A histopathologic study and its bearing on their pathogenesis journal J. Pediatr. Surg. volume 44 issue 11 pages 2223 9 year 2009 month November pmid 19944238 doi 10.1016 j.jpedsurg.2009.07.024 url http linkinghub.elsevier.com retrieve pii S0022 3468 09 00582 X ref References reflist External links EmbryologySwiss hdisqueembry triderm04 EmbryologyUNC genital 021 http embryology.med.unsw.edu.au Medicine images stage11cloacal.jpg Diagram at unsw.edu.au http www.ana.ed.ac.uk anatomy humat notes embryo urogenital cloacal.htm Overview at ana.ed.ac.uk developmental biology stub Gray s Development of urinary and reproductive systems Development of digestive system Category Embryology of urogenital system Category Embryology of digestive system ... more details
Infobox Embryology Name Laryngotracheal groove Latin sulcus laryngotrachealis GraySubject 235 GrayPage 1071 Image Gray947.png Caption The head and neck of a human embryo thirty two days old, seen from the ventral surface. The floor of the mouth and pharynx have been removed. Laryngo tracheal tube labeled at lower left, second from bottom. Image2 Caption2 System CarnegieStage Days 28 Precursor endoderm ref http www.llu.edu llu medicine anatomy glossary syllabus resp.html LLU Medicine Anatomy Histology Mentor Respiratory Bot generated title ref GivesRiseTo MeshName MeshNumber Code Terminologia Embryologica TE E5.5.3.0.0.0.2 The laryngotracheal groove is a precursor for the larynx and Vertebrate trachea trachea . The rudiment of the respiratory organs appears as a median longitudinal groove in the ventral wall of the pharynx. The groove deepens and its lips fuse to form a septum which grows from below upward and converts the groove into a tube, the Laryngotracheal groove or laryngo tracheal tube , the cephalic end of which opens into the pharynx by a slit like aperture formed by the persistent anterior part of the groove. Initially the cephalic end is in open communication with the foregut but eventually it becomes separated by indentations of mesoderm, the tracheoesophageal folds . When the tracheoesphageal folds fuse in the midline to form the tracheoesophageal septum , the foregut is divided into trachea ventrally and the esophagus dorsally. The tube is lined by endoderm from which the epithelial lining of the respiratory tract is developed. The cephalic part of the tube becomes the larynx, and its next succeeding part the trachea, while from its caudal end two lateral outgrowths, the right and left lung buds, arise, that branch into main primary , lobar secondary , segmental tertiary , and subsegmental bronchi and lead to development of the lungs.The Hox complex, FGF 10 fibroblast growth factor , BMP 4 bone morphogenetic protein , N myc a proto oncogene , syndecan ... more details
Unreferenced date December 2009 Triploblasty is a condition of the blastula in which there are three primary germ layer s the ectoderm , mesoderm , and endoderm . The germ layers form during gastrulation of the blastula . Additionally, the term may refer to any ovum in which the blastoderm splits into three layers. citation needed date January 2011 All higher and intermediate animals from flat worms to humans , arise from a triploblastic ovum. Triploblastic organisms are organisms which develop from such an ovum. Generally speaking, triploblastic organisms belong to the Bilateria subregnum. Triploblastic organisms generally possess bilateral symmetry, which is where the clade Bilateria takes its name. Simpler animals qualified as diploblasty diploblastic , such as cnidaria which include jellyfish, corals and hydra , possess two germ layers. Even simpler animals such as sea sponge sponges within the formally termed Porifera phylum contain no true tissues. See also Embryo Category Developmental biology Developmental biology stub ca Triplobl stia de Triploblast es Tribl stico fr Triploblastique it Triploblastico pl Tr jwarstwowce pt Tribl stico ru ... more details
Blood vessels first make their appearance in several scattered vascular areas that are developed simultaneously between the endoderm and the mesoderm of the yolk sac , i. e., outside the body of the embryo . Here a new type of cell, the angioblast or vasoformative cell , is differentiated from the mesoderm. These cells as they divide form small, dense syncytial masses, which soon join with similar masses by means of fine processes to form plexuses . Angioblasts are one of the two products formed from hemangioblasts the other being multipotential hemopoietic stem cell s . External links GrayPage 505 http www.medicine.uiowa.edu creative portfolio.asp?recordID ILLUSTRATION&index 2 Diagram at uiowa.edu http www.brown.edu Courses BI0032 stemcell vascu.htm Development of the vascular system , at brown.edu http 7e.devbio.com article.php?ch 15&id 156 Alternative Sources Of Angioblasts Gray s Human cell types derived primarily from mesoderm Category Embryology ... more details
Image Gray22.png thumb Human embryo of 2.6 mm. Image Gray458.png thumb Diagram of the vascular channels in a human embryo of the second week. After Eternod. The red lines are the dorsal aort continued into the umbilical arteries . The red dotted lines are the ventral aort , and the blue dotted lines the vitelline veins . Vitelline circulation refers to the system of blood flowing from the embryo to the yolk sac and back again. The yolk sac is situated on the ventral aspect of the embryo it is lined by endoderm , outside of which is a layer of mesoderm . It is filled with fluid, the vitelline fluid , which possibly may be utilized for the nourishment of the embryo during the earlier stages of its existence. Blood is conveyed to the wall of the sac by the primitive aort , and after circulating through a wide meshed capillary plexus , is returned by the vitelline veins to the tubular heart of the embryo. This constitutes the vitelline circulation, and by means of it nutritive material is absorbed from the yolk sac and conveyed to the embryo. External links GrayPage 54 http www.med.umich.edu lrc coursepages M1 embryology embryo 13cardiovascular system.htm Overview of three circulation systems Gray s Category Embryology of cardiovascular system ... more details
Infobox Embryology Name PAGENAME Latin GraySubject 6 GrayPage 47 Image Gray977.png Caption Human embryo about fifteen days old. Brain and heart represented from right side. Digestive tube and yolk sac in median section. Buccopharyngeal membrane labeled in upper left. Image2 Caption2 System CarnegieStage Days Precursor GivesRiseTo MeshName MeshNumber DorlandsPre m 08 DorlandsSuf 12522482 The region where the crescentic masses of the ectoderm and endoderm come into direct contact with each other constitutes a thin membrane, the buccopharyngeal membrane or oropharyngeal membrane , which forms a septum between the primitive mouth and pharynx . In front of the buccopharyngeal area, where the lateral crescents of mesoderm fuse in the middle line, the pericardium is afterward developed, and this region is therefore designated the pericardial area . External links EmbryologyUNC hednk 020a developmental biology stub Gray s Development of digestive system Category Embryology of digestive system de Rachenmembran ... more details
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