The mucosa (or mucous membrane), it has absorptive cells (also known as Enterocytes) are simple columnar cells with microvilli (or brush border);  goblet cells are plentiful and secrete mucus; it has Lieberkuhn’s intestinal crypts which are straight, unbranched tubular glands; The lamina propria is an abundant between crypt cross-sections. There are numerous cell types visible, including plasma cells, lymphocytes, eosinophils, and macrophages. It also has muscularis mucosae which is a smooth muscle layer. Another membrane, submucosa is a type of dense irregular connective tissue. The last membrane is the muscularis externa which is a smooth muscle with two orthogonal layers which are found in the inner circumferential layer and in the outer longitudinal layer.