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## Epithelium - Tight junctions: Membranes capable for preventing the movement of substances between cells (specialized). - Junctions that are formed; have specified a majority of the basement membrane and underlying connective tissue. - Epithelium is held together more tightly than other cells. -...

## Epithelium - Tight junctions: Membranes capable for preventing the movement of substances between cells (specialized). - Junctions that are formed; have specified a majority of the basement membrane and underlying connective tissue. - Epithelium is held together more tightly than other cells. - Cells with withstanding mechanisms and stress. ### Different from Endothelial Cells - Endothelial cells, like blood vessels and the walls of arteries and capillaries. ### Functions of Epithelium - Secretion: Digestive tract. - Absorbtion: Intestinal epithelia. - Protection: Cover surfaces, lungs can withstand. - Transport: Movement substances across membranes - Sensation: Nerve endings, signal for sensory sensations. - Movement: Ciliated epithelial cells and in moving substances. ### Characteristics of Epithelium - The most cellular tissue in the body. - Forms semi-permeable membranes - Avascular: Having few or no blood vessels. - Good nerve supply. - Cells are tightly packed together. - Rapid cell division. ### Cells of Epithelium - Are usually supported by their attachment membrane. - Inner connective tissue is made of proteoglycans reinforced by fine filament, known as the lamina propria. - Basal