{"id":3894,"date":"2012-07-08T18:36:47","date_gmt":"2012-07-08T16:36:47","guid":{"rendered":"http:\/\/codexvirtualis.fr\/codex\/?page_id=3894"},"modified":"2022-06-06T17:41:44","modified_gmt":"2022-06-06T15:41:44","slug":"premiers-pas-histologiques","status":"publish","type":"page","link":"https:\/\/codexvirtualis.fr\/codex\/de-lorganisation-interne\/premiers-pas-histologiques","title":{"rendered":"Premiers pas histologiques"},"content":{"rendered":"\n
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L’organisation interne des organismes peut \u00eatre \u00e9tudi\u00e9e \u00e0 partir de pr\u00e9parations histologiques.<\/p>\n\n\n\n

Il s’agit de fines sections dont l’\u00e9paisseur varie de 5 \u00e0 10 \u00b5m, coll\u00e9es sur des lames de verre, g\u00e9n\u00e9ralement color\u00e9es, et observ\u00e9es au microscope optique.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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\"Intestin<\/a>
Intestin de Triton en coupe transversale<\/figcaption><\/figure>\n\n\n\n

Voir l’image l\u00e9gend\u00e9e<\/a><\/p>\n\n\n\n

Sur cette pr\u00e9paration histologique d’intestin de Triton, diverses structures sont visibles.
De gauche \u00e0 droite se succ\u00e8dent trois tuniques :<\/p>\n\n\n\n

\u2022 <\/span>\u00e9pith\u00e9liale, dont la couleur dominante est le rouge, avec quelques taches bleu\u00e2tres ;<\/p>\n\n\n\n

\u2022 <\/span>conjonctive, principalement color\u00e9e en bleu ;<\/p>\n\n\n\n

\u2022 <\/span>musculaire, \u00e9galement de couleur rouge.<\/p>\n\n\n\n

Des \u00e9l\u00e9ments nerveux sont pr\u00e9sents au sein de la tunique musculaire. Ils forment les volumineuses taches rouges en bas de l’image.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Les coupes histologiques confectionn\u00e9es \u00e0 partir d’organismes animaux apparaissent compos\u00e9es de quatre types de tissus :<\/p>\n\n\n\n

\u2022 <\/span>le tissu \u00e9pith\u00e9lial ;<\/p>\n\n\n\n

\u2022 <\/span>le tissu conjonctif ;<\/p>\n\n\n\n

\u2022 <\/span>le tissu musculaire ;<\/p>\n\n\n\n

\u2022 <\/span>le tissu nerveux.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Litt\u00e9ralement, le terme \u00ab\u00a0histologie\u00a0\u00bb d\u00e9signe ainsi l’\u00e9tude des tissus.<\/p>\n\n\n\n

Il n’est cependant pas ais\u00e9 d’\u00e9noncer une d\u00e9finition du terme \u00ab\u00a0tissu\u00a0\u00bb.<\/p>\n\n\n\n

En premi\u00e8re approximation, un tissu peut \u00eatre d\u00e9crit comme un ensemble fonctionnel pluricellulaire.<\/p>\n\n\n\n

Il correspond \u00e0 un ensemble de cellules pr\u00e9sentant des caract\u00e8res morphologiques accus\u00e9s, souvent de m\u00eame origine embryologique, et concourant \u00e0 la r\u00e9alisation d’une fonction.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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La compr\u00e9hension et l’interpr\u00e9tation de toute pr\u00e9paration histologique passe par le rep\u00e9rage et l’identification des cellules qui la composent.<\/p>\n\n\n\n

\"Foie<\/a>
Foie de Souris en coupe transversale<\/figcaption><\/figure>\n\n\n\n

Voir l’image l\u00e9gend\u00e9e<\/a><\/p>\n\n\n\n

Le grossissement et la r\u00e9solution du microscope optique permettent de distinguer :<\/p>\n\n\n\n

\u2022 <\/span>le noyau, structure individualis\u00e9e contenant l’essentiel du mat\u00e9riel g\u00e9n\u00e9tique, il est nettement d\u00e9limit\u00e9 du fait de la pr\u00e9sence d’une enveloppe qui l’entoure ;<\/p>\n\n\n\n

\u2022 <\/span>le cytoplasme, form\u00e9 d’une solution dans laquelle baignent les divers composants cellulaires (\u00e0 l’exception du noyau, leur taille est trop faible pour qu’ils puissent \u00eatre r\u00e9v\u00e9l\u00e9s par la technique utilis\u00e9e et l’instrument employ\u00e9).<\/p>\n\n\n\n

La forme des cellules sugg\u00e8re l’emplacement de la membrane plasmique qui constitue la fronti\u00e8re entre la cellule et son environnement.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Les liens ci-dessous conduisent aux pages consacr\u00e9es \u00e0 chaque cat\u00e9gorie de tissus animaux.<\/p>\n\n\n\n

Certaines pages sont en cours de construction. Encore un peu de patience !<\/p>\n<\/div>\n<\/div>\n\n\n\n

<\/p>\n\n\n\n

<\/p>\n\n\n\n

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<\/p>\n\n\n\n

\"\"<\/a><\/figure>
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Le tissu \u00e9pith\u00e9lial<\/h2>\n\n\n\n

Une description illustr\u00e9e des caract\u00e9ristiques et de la diversit\u00e9 du tissu \u00e9pith\u00e9lial<\/a><\/p>\n<\/div><\/div>\n\n\n\n

<\/p>\n\n\n\n

<\/p>\n\n\n\n

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<\/p>\n\n\n\n

\"\"<\/a><\/figure>
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Le tissu conjonctif<\/h2>\n\n\n\n

Une description illustr\u00e9e des caract\u00e9ristiques et de la diversit\u00e9 du tissu conjonctif<\/a><\/p>\n<\/div><\/div>\n\n\n\n

<\/p>\n\n\n\n

<\/p>\n\n\n\n

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<\/p>\n\n\n\n

\"\"<\/a><\/figure>
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Le tissu musculaire<\/h2>\n\n\n\n

Une description illustr\u00e9e des caract\u00e9ristiques et de la diversit\u00e9 du tissu musculaire<\/a><\/p>\n<\/div><\/div>\n\n\n\n

<\/p>\n\n\n\n

<\/p>\n\n\n\n

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<\/p>\n\n\n\n

\"\"<\/a><\/figure>
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Le tissu nerveux<\/h2>\n\n\n\n

Une description illustr\u00e9e des caract\u00e9ristiques et de la diversit\u00e9 du tissu nerveux<\/a><\/p>\n<\/div><\/div>\n\n\n\n

<\/p>\n\n\n\n

<\/p>\n\n\n\n

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<\/p>\n","protected":false},"excerpt":{"rendered":"

L’organisation interne des organismes peut \u00eatre \u00e9tudi\u00e9e \u00e0 partir de pr\u00e9parations histologiques. Il s’agit de fines sections dont l’\u00e9paisseur varie de 5 \u00e0 10 \u00b5m, coll\u00e9es sur des lames de verre, g\u00e9n\u00e9ralement color\u00e9es, et observ\u00e9es au microscope optique. Voir l’image l\u00e9gend\u00e9e Sur cette pr\u00e9paration histologique d’intestin de Triton, diverses structures sont visibles.De gauche \u00e0 droite […]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":22,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-3894","page","type-page","status-publish","hentry"],"aioseo_notices":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/pages\/3894","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/comments?post=3894"}],"version-history":[{"count":25,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/pages\/3894\/revisions"}],"predecessor-version":[{"id":14577,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/pages\/3894\/revisions\/14577"}],"up":[{"embeddable":true,"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/pages\/22"}],"wp:attachment":[{"href":"https:\/\/codexvirtualis.fr\/codex\/wp-json\/wp\/v2\/media?parent=3894"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}