Answer to Question 1
The vascular or blood circulatory system is a closed system of vessels through which blood flows continuously in a figure eight, with the heart serving as a pump at the crossover point. On each loop of the figure eight, blood travels a simple route: heart to arteries to capillaries to veins to heart. The routing of blood through the digestive system is different, however. Blood is carried to the digestive system (as it is to all organs) by way of an artery, which (as in all organs) branches into capillaries to reach every cell. Blood leaving the digestive system goes by way of a vein. The hepatic portal vein, however, directs blood not back to the heart but to another organthe liver. This vein again branches into a network of small blood vessels (sinusoids) so that every cell of the liver has access to the newly absorbed nutrients that the blood is carrying. Blood leaving the liver then again collects into a vein, called the hepatic vein, which returns the blood to the heart. The route is thus heart to arteries to capillaries (in intestines) to hepatic portal vein to sinusoids (in liver) to hepatic vein to heart.
Answer to Question 2
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