In that Epitome, it is possible to read that "ileitis is a non-specific inflammation of the terminal portion of the ileum which sometimes spreads to the cecum causes ulceration of the intestinal mucosa, thickening and retraction of the intesti- nal wall... The diagnosis is bas...
these internal cylindrical structures may be most appropriately interpreted as digestive tracts, which would be, to date, the earliest-known occurrence of such features in the fossil record. If this interpretation is correct, their nature as one-way through-guts not only provides evidence for establ...
The absorption of nutrients, including calcium, occurs by their movement across the epithelium cell layer of the intestinal tract, which is composed of absorbing enterocytes, goblet cells, and other cell types. The surface of the absorbing enterocyte that faces the intestinal lumen is the brush bor...