Describe the structure and function of different types of epithelial tissues. Draw diagram of each type of epithelial tissue.
Describe the structure and function of different types of epithelial tissues. Draw diagram of each type of epithelial tissue.
The epithelial tissue forms the covering or lining of most of the organs. The cells of the epithelial tissue are tightly packed and form a continuous sheet. There is a small amount of cementing material between the cells and no intercellular space is present. The permeability of the epithelial tissue plays a great role in the exchange of materials among various organs it also plays an important role in osmoregulation. All epithelial tissues are separated by the underlying tissue by an extracellular fibrous basement membrane. Epithelial tissues are of following types:
a. Simple Epithelium: The simple epithelium is composed of a single layer of cells. This type of epithelial tissues forms the lining of blood vessels and alveoli. A thin layer of cells facilitates the exchange of substances; in such cases.
b. Cuboidal Epithelium: The cells are cube-shaped in the cuboidal epithelium. Linings of kidney tubules and ducts of salivary glands are composed of cuboidal epithelium. Cuboidal cells provide mechanical support. Cells of epithelium may play the role of secretion and then they are called glandular epithelium.
c. Columnar Epithelium: Cells are column-shaped in the columnar epithelium. Columnar epithelium facilitates secretion and absorption. For example; the lining of the intestine is composed of columnar epithelium. In some organs, columnar epithelium has cilia present on the outer surface. Cilia facilitate movements of certain substances. The ciliated epithelium in the respiratory tract pushes the mucus forward.
d. Stratified Epithelium: Cells of the stratified epithelium are in many layers. Skin is an example of stratified epithelium. Stratification of layers prevents wear and tear.
The epithelial tissue forms the covering or lining of most of the organs. The cells of the epithelial tissue are tightly packed and form a continuous sheet. There is a small amount of cementing material between the cells and no intercellular space is present. The permeability of the epithelial tissue plays a great role in the exchange of materials among various organs it also plays an important role in osmoregulation. All epithelial tissues are separated by the underlying tissue by an extracellular fibrous basement membrane. Epithelial tissues are of following types:
a. Simple Epithelium: The simple epithelium is composed of a single layer of cells. This type of epithelial tissues forms the lining of blood vessels and alveoli. A thin layer of cells facilitates the exchange of substances; in such cases.
b. Cuboidal Epithelium: The cells are cube-shaped in the cuboidal epithelium. Linings of kidney tubules and ducts of salivary glands are composed of cuboidal epithelium. Cuboidal cells provide mechanical support. Cells of epithelium may play the role of secretion and then they are called glandular epithelium.
c. Columnar Epithelium: Cells are column-shaped in the columnar epithelium. Columnar epithelium facilitates secretion and absorption. For example; the lining of the intestine is composed of columnar epithelium. In some organs, columnar epithelium has cilia present on the outer surface. Cilia facilitate movements of certain substances. The ciliated epithelium in the respiratory tract pushes the mucus forward.
d. Stratified Epithelium: Cells of the stratified epithelium are in many layers. Skin is an example of stratified epithelium. Stratification of layers prevents wear and tear.
