Intestines 01

Here at low magnification, is slide D05, the thin plastic section of the gastroduodenal junction. It is oriented so that most of the field is the duodenum and only a small portion of the pyloric stomach is shown, with the actual junction indicated at the arrow, and shown at higher magnification in Intestine 01A. The extensive folding of the mucosal epithelium (and lamina propria) into villi and crypts is obvious, with the letters "P" indicating where villi "end" and pits "begin". The muscularis mucosa [seen just to the left of the left-most asterisk (*)] APPEARS to end at the gastro-duodenal junction, but does NOT; it is actually continuous (but hard to see at this low magnification because of all the submucosal glands of the duodenum) and continues along a course roughly indicated by all the asterisks. The submucosal glands (of Brunner - "BG") are obvious, as is the muscularis externa ("ME"). Even at this low magnification it is possible to see the serosal mesothelium and to perceive that the two layers of the muscularis externa are, in some places - separated by a thin layer, which is where the myenteric plexus would be found.

Slide P-1, label to right, field O42/P42 of finder slide B, 2.5X objective