Anatom3DPeyer's patches
Noduli lymphoidei aggregati · Peyerovy plaky
Lymphatic & immune
Looks like
Oval clusters of lymph follicles in the wall of the lower small intestine (the ileum), visible from inside as raised patches.
What it does
Sample the gut contents and set up immune responses to germs in food.
Keeping it well
Enlarged patches can make the gut fold in on itself in children (intussusception): severe colic with red, jelly-like stools is an emergency.