The soluble nutrients from digestion (amino acids, sugars and soluble vitamins) travel from the intestine to the liver through the portal vein. The transport of lipids, cholesterol and fat-soluble vitamins is much more complex, since they are not soluble, they cannot be sent to the portal vein because there they would quickly produce fat deposits, and must be sent through the lymphatic system. Among the functions of the lymphatic system, two should be highlighted: its central role in the immune system, and its role in the transport of lipids and cholesterol from the diet. Lymphatic ducts from the intestine converge into the thoracic duct that joins the bloodstream near the entrance to the superior vena cava, where the lymph content passes into the systemic blood circulation.
True. Definitely , this mark the end of digestion and gives analysis of absorption of metabolites for use by the cells and tissues. Lipids are insoluble in water thus can not enter the blood stream without assistance of fat soluble medium thus they need to be absorbed by the lacteal to reach lymphatic system.
Explanation:
Water soluble substances -metabolites- are emptied into the blood stream by the hepatic portal vein. This is the blood vessels which drains the liver of water soluble metabolites to reach the cells.
Fat solube metabolites can not be transported directly into the portal vein, rather they are moved into villi in the walls of columnar epithelial cells lining the duodenum. Villi and microviilli increase surfaces area of the columnar epithelium of the duodenum for absorption.
They are made up of capillaries networks for reception of metabolites-amino acids and carbohydrates from the lumen of the duodenum,,and networks of capillaries which merged to form lymphatic vessels called Lacteal for reception of lipids and glycerol as Chyle. Through the lymphatic vessels they are empty into the blood stream.
The process of when a lake freezes in the winter and thaws in the spring without changing the size or shape is neither constructive or destructive! It's neither.
