One of the 4 major tissues in the human body is the epithelial tissue. It is found in the respiratory, digestive, and oral cavities, among other locations in the body. It is made up of densely packed cells with limited extracellular space, an apical/free surface exposed to the internal body or external environment, and a basal surface coupled to a thin basement membrane connecting to connective tissue. They obtain nutrients from the apical surface or by diffusion over their basal surface from the underlying connective tissue since they are avascular. They are also capable of regeneration, which is crucial because they are prone to strain.
One of the 4 major tissues in the human body is the epithelial tissue. It is found in the respiratory, digestive, and oral cavities, among other locations in the body. It is made up of densely packed cells with limited extracellular space, an apical/free surface exposed to the internal body or external environment, and a basal surface coupled to a thin basement membrane connecting to connective tissue. They obtain nutrients from the apical surface or by diffusion over their basal surface from the underlying connective tissue since they are avascular. They are also capable of regeneration, which is crucial because they are prone to strain.