They are instead mixed with bile from the liver to form smaller lipid packages called micelles. These can then be taken into the epithelial cells. Within the epithelial cell, the small lipids are taken up by the endoplasmic reticulum and packaged into vesicles called chylomicrons. These vesicles are then exocytosed out the other surface of the epithelium, where they are taken up by lymph vessels. They are then transported in the lymph to the cardiovascular system.
Hormones provide many important controls over digestion.
A protein hormone called gastrin stimulates secretion of acid into the stomach. Secretin stimulates the pancreas to secrete bicarbonate. CCK also stimulates the contraction of the gall bladder. There are some excellent figures in Chapter 42. Please study all of those in Section 42.5, and review by looking at Figure 42.12.