Biology

Biology Department Courses

DIGESTIVE SYSTEM, THE ILEUM, AT LOW MAGNIFICATION:

This is a cross section of the ileum region of the small intestine.  The lumen (L) is the space where the digestive material passes down the tract.  The finger-like projections, called villi, are lined with simple columnar epithelium (E).  Underneath the villi is the support layer called the submucosa (SM); it is functionally equivalent to the dermis of the skin!   Underlying the submucosa are two layers of smooth muscle, the inner circular muscle (IM) and the outer longitudinal layer (OM).


DIGESTIVE SYSTEM, THE ILEUM, AT HIGHER MAGNIFICATION:

This is a cross section of the ileum region of the small intestine.  The villi are lined with simple columnar epithelium (E).  Each villus is covered with simple columnar epithelium and supported by small extension of support tissue called lamina propria (LP).