MEDICAL PHYSIOLOGY

Detailed explanation-1: -Nearly all dietary lipid is transported in chylomicrons from the gut to the blood through the lymphatic system by entering specialized lymphatic vessels, referred to as lacteals, in the villi of the intestine (Fig. 1).

Detailed explanation-2: -The mucosa that lines the small intestine is covered with fingerlike projections called villi. There are blood capillaries and special lymph capillaries, called lacteals, in the center of each villus. The blood capillaries absorb most nutrients, but the fats and fat-soluble vitamins are absorbed by the lacteals.

Detailed explanation-3: -A lacteal, the blunt‐ended lymphatic capillary at the center of each villus in the small intestine, is a main route for drainage of dietary lipids and lipid‐soluble nutrients in the form of lymph, which returns to the systemic circulation via the thoracic duct 1, 2.

Detailed explanation-4: -In the small intestines bile emulsifies fats while enzymes digest them. The intestinal cells absorb the fats. Long-chain fatty acids form a large lipoprotein structure called a chylomicron that transports fats through the lymph system.

Detailed explanation-5: -The lacteals merge to form larger lymphatic vessels that transport the chyle to the thoracic duct where it is emptied into the bloodstream at the subclavian vein. At this point, the fats are in the bloodstream in the form of chylomicrons.