Lumen (anatomy)
From Wikipedia, the free encyclopedia
The lumen (pl. lumina) is the interior of a vessel within the body, such as the small central space in an artery or vein, or any of their relating vessels through which blood flows. Lumen may also refer to the inner membrane space of a chloroplast, Golgi apparatus or mitochondrion. On a larger scale, the interior of the gastrointestinal tract may also be referred to as its lumen, and likewise the pathways of the bronchi in the lungs.
tissue layers