<P> The portal venous system is responsible for directing blood from parts of the gastrointestinal tract to the liver . Substances absorbed in the small intestine travel first to the liver for processing before continuing to the heart . Not all of the gastrointestinal tract is part of this system . The system extends from about the lower portion of the esophagus to the upper part of the anal canal . It also includes venous drainage from the spleen and pancreas . </P>
<P> The portal venous system is responsible for directing blood from parts of the gastrointestinal tract to the liver . Substances absorbed in the small intestine travel first to the liver for processing before continuing to the heart . Not all of the gastrointestinal tract is part of this system . The system extends from about the lower portion of the esophagus to the upper part of the anal canal . It also includes venous drainage from the spleen and pancreas . </P>
where does the venous blood go after leaving the small intestine
where does the venous blood go after leaving the small intestine
the liver
the liver