<p style="text-align: justify;"><span id="result_box" lang="fr"><span class="hps">L'intestin grêle</span> <span class="hps">d'un</span> <span class="hps">cheval</span> <span class="hps">de taille</span> <span class="hps">moyenne</span> <span class="hps">(450</span> <span class="hps">kg</span><span>)</span> <span class="hps">est d'environ 20</span> <span class="hps">mètres de long</span><span>.</span> <span class="hps">Il est</span> <span class="hps">anatomiquement</span> <span class="hps">divisé en</span> <span class="hps">trois</span> <span class="hps">segments</span> </span>:</p>
<p style="text-align: justify;"><br /><span id="result_box" lang="fr"><strong><span class="hps">Duodénum</span></strong> <span class="hps">-</span> <span class="hps">les</span> <span class="hps">1-1,5</span> <span class="hps">premiers mètres</span>. <span class="hps">La voie biliaire</span> <span class="hps">et</span> <span class="hps">pancréatique</span> <span class="hps">vident</span> <span class="hps">leur contenu</span> <span class="hps">dans le duodénum</span> <span class="hps">à la jonction avec</span> <span class="hps">le jéjunum</span>.<br /> <strong><span class="hps">Jéjunum</span></strong> <span class="hps">-</span> <span class="hps">la partie médiane de</span> <span class="hps">l'intestin</span> <span class="hps atn">(</span><span>&gt;</span> <span class="hps">80</span><span>% de la longueur</span><span>)</span><span>.</span> <span class="hps">La paroi du</span> <span class="hps">jéjunum</span> <span class="hps alt-edited">regorge de</span> <span class="hps">glandes</span> <span class="hps">qui sécrètent des</span> <span class="hps alt-edited">enzyme</span> <span class="hps">digestives</span> <span class="hps">et des tampons</span> <span class="hps">dans la lumière</span><span>.</span> <span class="hps">Le</span> <span class="hps">jéjunum</span> <span class="hps">a une grande</span> <span class="hps">surface</span> <span class="hps">d'absorption</span><span>,</span> <span class="hps">et</span> <span class="hps">est le site</span> <span class="hps">majeur</span> <span class="hps alt-edited">pour</span> <span class="hps">l'absorption des nutriments</span> <span class="hps">dont les vitamines</span> <span class="hps">et les minéraux.</span><br /> <strong><span class="hps">Iléon</span></strong> <span class="hps">-</span> <span class="hps">les derniers</span> <span class="hps alt-edited">1-2 mètres</span> <span class="hps">de l'intestin grêle</span>. <span class="hps">La</span> <span class="hps">structure et la fonction</span> <span class="hps">de</span> <span class="hps">l'iléon</span> <span class="hps">est</span> <span class="hps">très semblable à celle</span> <span class="hps">du jéjunum</span>.</span><br /><br /><span id="result_box" lang="fr"><span class="hps">Le</span> <span class="hps">cheval n'a pas de</span> <span class="hps">vésicule biliaire</span><span>.</span> <span class="hps">La</span> <span class="hps">bile</span><span>, qui est produite</span> <span class="hps">par le foie,</span> <span class="hps">est</span> <span class="hps">donc</span> <span class="hps">sécrétée</span> <span class="hps">en continu dans</span> <span class="hps">l'intestin grêle.</span> <span class="hps alt-edited">Les solides</span> <span class="hps">biliaires</span> <span class="hps">(phospholipides</span> <span class="hps">et les sels biliaires</span><span>)</span> <span class="hps">aident</span> <span class="hps">à</span> <span class="hps">l'émulsification</span> <span class="hps alt-edited">de lipides</span>, <span class="hps">et</span> <span class="hps">sont un</span> <span class="hps">pré-requis pour</span> <span class="hps">la digestion des lipides</span>. <span class="hps">Le pancréas</span> <span class="hps">sécrète un liquide</span> <span class="hps alt-edited">riche en bicarbonate</span> <span class="hps">qui neutralise</span> <span class="hps">le contenu acide</span> <span class="hps atn alt-edited">du </span><span class="alt-edited">digesta de l'estomac</span><span>.</span> <span class="hps">Le contenu gastrique</span> <span class="hps alt-edited">est neutralisé</span> <span class="hps">à quelques mètres</span> <span class="hps">de</span> <span class="hps">son émergence</span> <span class="hps">dans l'intestin grêle</span><span>.</span> <span class="hps">Le pancréas</span> <span class="hps">sécrète</span> <span class="hps">aussi des enzymes</span> <span class="hps">qui hydrolysent</span> <span class="hps atn">les protéines (</span><span>trypsine</span>)<span>, les graisses</span> <span class="hps atn">(</span>lipase) <span class="hps">et l'amidon</span> <span class="hps atn">(</span><span>amylases</span>). <span class="hps">Les enzymes</span> <span class="hps">sécrétées</span> <span class="hps">par les glandes</span> <span class="hps">de la paroi intestinale</span> <span class="hps">continuent</span> <span class="hps">à digérer</span> <span class="hps alt-edited">les produits finaux</span> <span class="hps">provenant des réactions</span> <span class="hps">des enzymes pancréatiques</span> <span class="hps">en</span> <span class="hps alt-edited">petits éléments</span> <span class="hps">qui peuvent être absorbés</span> <span class="hps">par les cellules de</span> <span class="hps">l'épithélium intestinal.</span></span></p>
<p style="text-align: justify;">&nbsp;</p>
<p style="text-align: justify;"><span id="result_box" lang="fr"><span class="hps">La</span> <span class="hps">vitesse de transport</span> <span class="hps">à travers</span> <span class="hps">l'intestin grêle</span> <span class="hps">est d'environ</span> <span class="hps">20</span> <span class="hps">cm par</span> <span class="hps alt-edited">minute, </span><span class="alt-edited">donnant ainsi</span> <span class="hps alt-edited">à l'intestin grêle</span> <span class="hps">d'environ 1,5</span> <span class="hps">heure pour digérer</span> <span class="hps alt-edited">les aliments et les nutriments</span> <span class="hps alt-edited">extraits</span>. <span class="hps">Dans la dernière partie</span> <span class="hps">de l'iléon</span> <span class="hps alt-edited">le digesta</span> <span class="hps alt-edited">s'accumule</span> <span class="hps">avant d'être</span> <span class="hps alt-edited">expulsé</span> <span class="hps">sous pression dans</span> <span class="hps">le gros intestin</span> <span class="hps">à la jonction entre</span> <span class="hps">le côlon et</span> <span class="hps">le caecum</span>. <span class="hps alt-edited">La vidange</span> <span class="hps">de l'iléon</span> <span class="hps">semble avoir lieu</span> <span class="hps alt-edited">3 à 6</span> <span class="hps">fois par heure</span><span>,</span> <span class="hps">et fournit</span> <span class="hps">0,2 à 1,5</span> <span class="hps">litres de</span> <span class="hps">contenu intestinal</span> <span class="hps alt-edited">au</span> <span class="alt-edited">gros intestin</span> <span class="hps alt-edited">chaque fois.</span></span><br />&nbsp;<br /><span id="result_box" lang="fr"><span class="hps">Les</span> <span class="hps">sécrétions digestives</span> <span class="hps alt-edited">augmentent la teneur en</span> <span class="hps">eau</span> <span class="hps alt-edited">du </span> <span class="hps">digesta</span> <span class="hps">jusqu'à ce qu'il ait</span> <span class="hps">la consistance d'une</span> <span class="hps">soupe épaisse</span> <span class="hps">qui peut être</span> <span class="hps">propulsée à travers</span> <span class="hps">l'intestin</span> <span class="hps">long et</span> <span class="hps alt-edited">courbe</span>. <span class="hps alt-edited">Au niveau de </span> <span class="hps">l'iléon terminal</span> <span class="hps">la teneur en eau</span> <span class="hps">est d'environ 96</span>% <span class="hps atn">(</span>4% <span class="hps">de</span> <span class="hps">matière sèche</span>) <span class="hps alt-edited">sur un régime</span> <span class="hps">riche en</span> <span class="hps alt-edited">fourrages</span>, <span class="hps">et</span> <span class="hps alt-edited">de l'ordre</span> <span class="hps">de 90</span><span>% à 96</span>% <span class="hps alt-edited">sur une alimentation</span> <span class="hps alt-edited">contenant </span> <span class="hps">une plus grande proportion</span> <span class="hps">de grains et de</span> <span class="hps alt-edited">concentrés du commerce</span>.</span><br /><br /></p>