The mucosa of the small intestine is lined by a simple columnar epithelium which consists primarily of absorptive cells (enterocytes), with scattered goblet cells and occasional enteroendocrine cells.In crypts, the epithelium also includes Paneth cells and stem cells.he mucosa of the small intestine is characterized by evagination into plicae and villi, which increase the surface area for nutrient absorption, and by short tubular invaginations, the crypts, which provide a protected site for stem cells.
The following are sites where you can give a subcutaneous injection: 1  Abdomen: Uncover your abdomen. 2  Thigh: Uncover the entire leg. 3  Lower back: Uncover the back from the waist to the top of the buttocks.  Upper Arm: Uncover the arm to the shoulder.
These injections are given because there is little blood flow to fatty tissue, and the injected medication is. generally absorbed more slowly, sometimes over 24 hours. Some medications that can be injected. subcutaneously are growth hormone, insulin, epinephrine, and other substances. Preparing to give medication. Subcutaneous injections are not given if the skin is burned, hardened, inflamed, swollen, or damaged by a. previous injection. 1. Wash your hands thoroughly. This is the best way to prevent infection.