Tissues
Epithelial tissues are the linings and covering of surfaces with one side toward the inner (gut) or outer environment (skin) and the other side attached to cells below. For example, epithelium forms the skin, the lining of the digestive tract, glands and the lining of blood vessels. The shapes of epithelial cells vary from cuboidal, to squamous (like pancakes), to columnar (elongated). Simple columnar epithelial tissue lines most of the digestive tract.
|
Connective tissue varies greatly but has in common the fact that they have a cellular component and an extracellular component made by the cells of the tissues. One group of connective tissue contains the loose, dense-irregular and dense regular. The submucosa is a layer of loose connective tissue containing the large blood and lymph vessels and nerves, and lies between the mucosa and muscularis externa. The collagen fibers are coarser than those in the lamina propria.
|
Muscle tissue has three major forms, smooth muscle tissue is the one found in the digestive system. You can find it on the walls most digestive organs, especially the walls of the stomach. It helps to churn foods and other stomach contents.
|