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| | The evolution of embryological development |
 | | The ganglia form in the ectoderm, and they must be interconnected to works as an animal behavior guidance system. | | | But the neural tube is the center of its behavior guidance system: It selects the kind of behavior for each situation, insofar as it has whole-body behavior at all. | | | In the same way, it probably also enables reproductive causation to shape the body and its organs in whatever way that is useful in generating behavior without disrupting the nervous system, as it surely does in proterostomes with its ganglia and nerves running throughout the body. |
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http://www.twow.net/ObjText/OtkCbGeRRS04D.htm
(8435 words)
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| | Evolutionary Developmental Biology |
| | The skin and its precursor the ectoderm is not responsible. | | | There are, in fact, many species of anuran and urodele amphibians in which the lens can form in the absence of the optic cup, prior interactions of the ectoderm with endoderm and/or mesoderm being sufficient. | | | The classical story of the development of the eye is often quoted as an example of embryonic induction. |
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http://www.leeds.ac.uk/chb/lectures/edb12.html
(3132 words)
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| | Eye Problems and Ectodermal Dysplasia (edeye.htm) |
| | The ectodermal dysplasias are a diverse group of conditions and over a 100 different types have been described. | | | As already discussed, structures of the eye formed from the ectoderm are affected by ED. | | | How different structures and functions of the eye are affected by ED will be covered, leading into the treatments available for different ocular problems, and to finish, a look to the future. |
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http://www.ectodermaldysplasia.org/edeye.htm
(1704 words)
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| | [No title] |
| | Where the hindgut meets ectoderm in the rectum What is the relationship of the two pulmonary arteries in the lung hilus? | | | Endoderm From what does the ligamentum teres hepatis arise? | | | - Septum transversum - pleuroperitoneal folds - body wall - dorsal mesentery of esophagus What four things arise from surface ectoderm? |
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http://umed.med.utah.edu/usmle/PDA/Anatomy.txt
(10754 words)
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| | Evidence for non-axial A/P patterning in the nonneural ectoderm of Xenopus and zebrafish pregastrula embryos |
| | These regions correspond to head, trunk and tail ectoderm and may represent the beginnings of functional segmentation of nonneural ectoderm, as suggested in the concept of the 'ectomere'. | | | We investigate which posteriorizing signals might contribute to such distinct non axial ectodermal patterning in the A/P axis and provide evidence that both FGF and a Wnt family member contribute towards the final A/P pattern of GATA expression in nonneural ectoderm. | | | Evidence for non-axial A/P patterning in the nonneural ectoderm of Xenopus and zebrafish pregastrula embryos |
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http://www.ijdb.ehu.es/abstract.sept98/42-64.htm
(295 words)
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| | Contribution of ectoderm-endoderm boundary to initiation of teeth and adenohypophysis |
| | Therefore, the aim of this study is to elucidate the involvement of the ectoderm-endoderm boundary in the initiation of both organs. | | | In mammals, however, there is no direct evidence for the contribution of the epithelial boundary between foregut endoderm and oral ectoderm to the development of teeth and adenohypophysis. | | | Methods: The germ layers were traced by means of DiI/DiO (molecular probe inc.) in long-term culture (LTC), in which whole rat embryo culture (WEC) is followed by the maxillary and mandibular organ culture. |
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http://iadr.confex.com/iadr/2004Hawaii/techprogram/abstract_46651.htm
(354 words)
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| | eMedicine - Ectodermal Dysplasia : Article by Carola Duran-McKinster, MD |
| | Medicine is a constantly changing science and not all therapies are clearly established. | | | Typical cleft lip/palate and maxillary hyperplasia in a patient with Rapp-Hodgkin syndrome. | | | Ectrodactyly observed in an individual with ectodermal dysplasia, ectrodactyly, and cleft lip/palate syndrome. |
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http://www.emedicine.com/derm/topic114.htm
(2898 words)
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| | Dorlands Medical Dictionary |
| | extraembryonic ectoderm, a derivative of epiblast or ectoderm located outside the body of the embryo. | | | sis) a disorder based on congenital maldevelopment of the organs of ectodermal derivation, i.e., nervous system, retina, eyeball, and skin. | | | to-morf) an individual having a type of body build in which tissues derived from the ectoderm predominate: there is a preponderance of linearity and fragility, with large surface area, thin muscles and subcutaneous tissue, and slightly developed digestive viscera, as contrasted with endomorph and mesomorph. |
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http://www.mercksource.com/pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_e_02zPzhtm
(3454 words)
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| | Interactive Fly, Drosophila |
| | For example, EGL-17 directs the movement of the sex myo-blasts in the gonad and FGF8 is required for the migration of the mesoderm into the primitive streak of vertebrate embryos and later for heart development (Burdine, 1998; Sun, 1999; Reifers, 2000). | | | The Htl receptor is essential for the development of various mesoderm lineages, including cardiac tissues, hindgut visceral musculature, and the body wall muscles. | | | Both ths and pyr are expressed in the neurogenic ectoderm during the spreading of the internal mesoderm in gastrulating embryos. |
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http://www.sdbonline.org/fly/newgene/fgfr1-1.htm
(3472 words)
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| | Spemann's induction experiments |
| | Such certainty would come when he was able to move an optic cup into an ectopic location and observe whether lenses had been formed. | | | Spemann claimed that contact of the optic vesicle with the overlying ectoderm was needed to turn that ectoerm into a lens, but he did not know whether or not it was a sufficient cause. | | | Moreover, he did not know yet whether the optic cup instructed the ectoderm to form a lens or merely acted as a trigger to permit a pre-existing potency to become expressed. |
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http://zygote.swarthmore.edu/regul2.html
(1482 words)
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| | Organizer molecules |
| | Salome Gluecksohn Waelsch (3) has claimed that Else Wehmeier was actually the first person who observed that dead organizer tissue still induced the competent ectoderm]. | | | The search for the "organizer molecule" was one of the first worldwide biological research programs. | | | Holtfreter (4) followed this up with his exogastrulation studies wherein the dorsal mesoderm failed to make contact with the overlying ectoderm. |
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http://zygote.swarthmore.edu/regul3.html
(780 words)
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| | Developmental Biology Online: Pathway For The Induction of the AER |
| | The limb is a complicated organ, and new research makes it seem even more complex. | | | Recombination experiments show that the limbless ectoderm is unable to form an AER, even when placed on wild-type limb mesoderm. | | | The analysis of development of the tetrapod limb has provided biologists with some of its greatest successes in understanding development, but it also keeps posing some of our greatest challenges. |
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http://www.devbio.com/article.php?ch=16&id=160
(1250 words)
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| | eMedicine - Trunk, Embryology : Article by Hongshik Han, MD |
| | These arches are separated further into external ectoderm-lined pharyngeal clefts and internal endoderm-lined pharyngeal pouches. | | | Failure of mesenchymal cells to migrate from the somatic mesoderm between the surface ectoderm and the urogenital sinus during the fourth week of development results in failure of striated muscle development. | | | The conglomeration of primitive streak–derived mesenchymal cells migrates in between the ectoderm and endoderm, forming the embryonic mesoderm. |
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http://www.emedicine.com/plastic/topic217.htm
(1529 words)
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| | intag - Intelligent Agents |
| | As an e-membranes behaves as a living bio-membranes with its corresponding ectoderm, mesoderm, and ectoderm, Websites could be enabled to make its content evolve by itself and at the same time to infer its users' behavior patterns. | | | Darwin networks may retrieve intelligence of different markets, to consolidate and equalize it. | | | This is a Knowledge Management breakthrough because with these Artificial Intelligent e-membranes, "only one click" super Search Engines could be easily implemented. |
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http://www.intagsolutions.com/references/contact.php
(542 words)
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| | VE Glossary |
| | Orienting response or reflex that encourages fetus to automatically turn its head toward a light source | | | Ectodermal thickenings that form olfactory epithelium and olfactory nerves | | | Ectodermal thickening in amniotic sac floor; Forerunner of nervous system (spinal cord and brain) |
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http://www.visembryo.com/baby/gloss.html
(4499 words)
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| | Ectoderm |
| | The ectoderm gives rise to various tissues including the skin and nervous system. | | | The ectoderm is one of the three germ layers of the developing embryo, the other two being the mesoderm and the endoderm. |
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http://www.theezine.net/e/ectoderm.html
(53 words)
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| | AllRefer.com - ectoderm (Cell Biology) - Encyclopedia |
| | In higher animals, such as those of the phyla Echinodermata and Chordata, a third, middle layer, the mesoderm, is formed between the ectoderm and endoderm during gastrulation, and the process is termed triploblastic development. | | | In the development of animals of the phyla Porifera, Ctenophora, and Cnidaria, these two primary layers give rise to all the tissues and organs of the animals, a process known as diploblastic development. | | | In animals of some phyla, such as the Mollusca and Annelida, the fate of particular cells of the embryo is determined in the earliest stages of the fertilized egg and may even be fixed at or before fertilization. |
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http://reference.allrefer.com/encyclopedia/E/ectoderm.html
(290 words)
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| | Sonic hedgehog |
| | This lack of signalling from the ectodermal layer is responsible for the absence of Shh expression. | | | There are several genes that play important roles in the signalling pathways of the limb development process. | | | This suggests also that signals resulting in the interactions within the developing limb exist before the apical ridge forms. |
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http://www.ucalgary.ca/UofC/eduweb/virtualembryo/sonic.html
(1539 words)
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| | Ectoderm |
| | The ectoderm, like the other two layers, forms at the gastrulation stage in embryonic development (when the digestive system is developing). | | | The ectoderm is outermost of the three germ layers of the developing embryo, the other two being the mesoderm and the endoderm. | | | In vertebrates, the ectoderm can be distinguished as three parts, each giving rise to different tissues: |
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http://www.worldhistory.com/wiki/E/Ectoderm.htm
(138 words)
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| | Developmental Biology Online: Vertical and Horizontal Signals from the Organizer |
| | First, there is some evidence that planar signals may be involved in the neuralizing activities of the organizer. | | | If planar signals traveling from the dorsal blastopore lip through the ectoderm are responsible for neural induction, then the original source of such signals should be the epithelium of the dorsal marginal zone rather than the deep mesenchyme cells of that organizer zone. | | | Doniach and her colleagues (1992) showed that instructive, positionally specific information is provided by planar signals passing through the ectoderm. |
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http://www.devbio.com/article.php?ch=10&id=130
(1006 words)
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| | Ectoderm |
| | In vertebrates, for instance, the embryonic ectoderm differentiates into the skin and also the nervous system. | | | The outer basic layer of tissue in those animals with true tissues. |
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http://www.cartage.org.lb/en/themes/Reference/dictionary/Metazoan/E/Ectoderm.html
(28 words)
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| | Hyalin (L. variegatus) |
| | Such a pattern provides evidence suggesting that patterns of hyalin gene expression are not strictly delimited by lineage but may instead reflect a zone of overlapping and counteracting signals used in establishing the oralñaboral boundary. | | | Concurrent with this morphogenesis, the ectoderm and endoderm change in their relative affinities for hyalin; ectoderm cells retain an affinity while endoderm cells lose their affinity (Burdsal et al., 1991). | | | First, the oral ectoderm has no signal by in situ RNA hybridization analysis except for a thin strip of ectoderm adjacent to the ciliary band. |
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http://www.bio.davidson.edu/courses/genomics/mirror/Urchin/u1lvhl.htm
(1334 words)
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| | ectoderm -- Encyclopædia Britannica |
| | By the 19th day of human embryonic development, ectoderm along the mid-back portion of the elongated embryo becomes thicker than adjoining ectoderm. | | | the innermost of the three germ layers, or masses of cells (lying within ectoderm and mesoderm), which appears early in the development of an animal embryo. | | | In vertebrates, ectoderm subsequently gives rise to hair, skin, nails or hooves, and the lens of the eye; the epithelia (surface, or lining, tissues) of sense organs, the nasal cavity, the sinuses, the mouth (including tooth enamel), and the anal canal;... |
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http://www.britannica.com/eb/article-9031948?tocId=9031948
(725 words)
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| | ectoderm |
| | outermost of the three germ layers of the embryo (the other two being mesoderm and endoderm); ectoderm gives rise to epidermis and neural tissue. |
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http://crisp.cit.nih.gov/Thesaurus/00002534.htm
(24 words)
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| | The Mosby Medical Encyclopedia: ectoderm@ HighBeam Research |
| | The ectoderm makes the nervous system; the organs of special sense, as the eyes and ears; the epidermis, and epidermal tissue, as fingernails, hair, and skin glands; and the mucous membranes of the mouth... | | | ectoderm, the outer of the three main cell layers of a young fetus (embryo). |
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http://www.highbeam.com/library/doc0.asp?DOCID=1P1:28731676&refid=ip_encyclopedia_hf
(130 words)
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| | Biology 104 Spring 2004 - Ectoderm |
| | Another part of the somatic ectoderm is the stomodeum | | | What parts of the body develop from ECTODERM: | | | The dermis is the leathery, mesodermal inner layer of the skin, made of mesenchymal cells, and tightly-woven collagen protein |
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http://www.bio.unc.edu/courses/2003spring/biol104/lecture17.html
(1418 words)
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| | LIFE BEGINS AT CONCEPTION |
| | The pre-embryonic period includes the formation of the three primary germ layers, the ectoderm, mesoderm, and endoderm, from which come the organs of the human body. | | | The Embryonic Period is characterized by dramatic cell differentiation from the fourth through the eighth week, so that the beginnings of all essential structures of the human body are present. |
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http://www.biblescripture.net/prolife.html
(2216 words)
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| | Morphologic development (from nervous system, human) -- Encyclopædia Britannica |
| | The neural plate elongates, and its lateral edges rise and unite in the midline to form the neural tube, which will develop into the central nervous system. | | | By 18 days after fertilization, the ectoderm of the embryonic disk thickens along what will become the dorsal midline of the body, forming the neural plate and, slightly later, the primordial eye, ear, and nose. |
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http://www.britannica.com/eb/article?tocId=75527&ct=eb&ref=news1004view
(684 words)
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| | Ectoderm, Mesoderm and Endoderm |
| | On the other hand, the Ectoderm also gives rise to the Central Nervous System. | | | For example, the Ectoderm gives rise to the epidermis and its derrivatives such as nails, hair and teeth. | | | They are the Ectoderm (shown in the diagram as blue), Mesoderm (red) and Endoderm (yellow). |
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http://www.luc.edu/depts/biology/dev/layer.htm
(69 words)
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| | Energy Citations Database (ECD) - Energy and Energy-Related Bibliographic Citations |
| | Availability information may be found in the Availability, Publisher, Research Organization, Resource Relation and/or Author (affiliation information) fields and/or via the "Full-text Availability" link. | | | For a journal article, please see the Resource Relation field. | | | Protein kinase C and regulation of the local competence of Xenopus ectoderm |
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http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=5696760
(101 words)
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| | Drosophila tissue and organ development: Ectoderm |
| | Dichaete (also known as Sox box protein 70D) | | | The ectoderm is the outer germ layer of the embryo, to be distinguished from the endoderm and mesoderm. | | | Epidermis, derived from ectoderm, is the outer epithelial layer of the embryo, larva and adult; it secretes cuticle, the exoskeleton of the fly. |
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http://www.sdbonline.org/fly/aimorph/ectoderm.htm
(67 words)
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| | MSN Encarta - Dictionary - ectoderm |
| | Click here to search all of MSN Encarta | | | Search for "ectoderm" in all of MSN Encarta |
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http://encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861607469
(62 words)
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