The lumen is the opening inside a tubular body structure that is lined by body tissue known as an epithelial membrane. ... When the walls of the intestine thicken and cause the lumen to become narrower, it can lead to problems such as strictures (narrowed parts of the intestine).

What does narrow lumen mean?

Narrow Lumen means Lumen: A luminous term referring to the channel within a tube such as a blood vessel or to the cavity within a hollow organ such as the intestine. ... ... For example, in arteriosclerosis, fat deposits narrow the lumen of the artery.

Why is the small intestine narrow?

Mucosal folds: The inner surface of the small intestine is not flat, but thrown into circular folds. This not only increases the surface area, but helps regulate the flow of digested food through your intestine.