Intestines 01A

Here, at higher magnification, is the region near the arrow in Intestine 01. The large asterisk is placed at the point where the mucosal epithelium changes rather abruptly from that lining the stomach (simple columnar, all mucous surface cells) to that lining the small and large intestines (simple columnar with several cell types, including the predominant tall columnar enterocyte and the very distinctive goblet cell). Because the apical mucous droplets of the goblet cells get extracted during routine processing, each goblet cell shows up with an empty "hole" (such as at the small asterisk) in the otherwise fairly eosinophilic epithelium; this is so characteristic that it can even be seen at very low magnification (look back at Intestine 01), which makes it fairly easy to distinguish the intestines from the stomach. Because the cells of the mucosal epithelium turn over fairly rapidly (every 3-5 days), it is common to find cells undergoing mitosis, such as those just below the "M".

Slide P-1, label to right, field O42,3 of finder slide B, 16X objective