Epithelial components of the organs of the digestive system are derived from endoderm whereas connective tissue and muscle components are derived from mesoderm. At the 3-4th of development, as a result of cephalocaudal and lateral foldings of the embryo, a portion of the endoderm-lined yolc sac cavity is incorporated in the embryo to from the primitive gut. Primitive gut is composed of four main regions which are pharyngeal gut, foregut, midgut, and hindgut; respectively. Intestines are derived from foregut, midgut and hindgut. The development of the intestines is characterised by lengthening, widening, thickening, histological and positional changes. In this manuscript we tried to review the morphological and functional development of the small and large intestines with the aid of pictures obtained from various stages of prenatal and postnatal development the intestines of rats. Previous reviews lack of information on both histological and functional development of the small and large intestines.
Keywords: Development, large intestines, small intestines