Lymphatic capillaries form blind-ended vessels in all organs (referred to as lacteals in the intestine). These vessels converge and transition into collecting lymphatic vessels that are surrounded by muscle (red lines overlaying lymphatic vessels). Collecting vessels are interrupted by LNs. Collecting vessels and the LNs are surrounded by adipose tissue. The largest collecting vessel, the thoracic duct, drains lymph collected from all organs into the bloodstream at the subclavian vein. Insets detail the structure of lymphatic capillaries with respect to lipoprotein absorption. In tissues such as skin and lung, button-like junctions separate endothelial cells and create flaps, which allow receptor-independent entry of molecules into lymph. In intestine, large pores may form at the tips. The precise artery-capillary organization is unknown. Entry of discoidal HDL into skin lymph may be mediated by receptors through binding of SR-B1 (left inset), but more work is needed to confirm this. The right inset depicts the fenestrated transition from arterial capillary to venous blood capillary around each intestinal lacteal. Smaller nutrients not packaged in chylomicrons enter the blood vasculature that leads to the portal vein, but chylomicrons are too large. They enter the lacteal vessels by means of size exclusion, which also plays a key role in routing of HDL into lymph in other organs. Macrophages and DCs endocytose at least some molecules in intestinal villi, reducing their transit into the lacteal vessels, even if they bypass entry into the blood vasculature.