STRATIFIED EPITHELIA

-
These epithelia consist of two or more layers of cells. In which only the bottom layer rests on the basement membrane. Stratified epithelia are further classified into subtypes according to the shape of the cells in the superficial layer. The layer on the free surface of the epithelium.

Stratified Epithelia

This group of epithelia has the following types.

  • stratified squamous epithelium
  • stratified cuboidal epithelium
  • stratified columnar epithelium
  • A special type of the stratified epithelia is called transitional epithelium.

Popular posts from this blog

STRATIFIED CUBOIDAL EPITHELIUM

-
Image
The stratified cuboidal epithelium consists of two or three layers of cuboidal cells. This type of epithelium has a very restricted distribution in the human body. It only occurs as the lining of the larger ducts of some exocrine glands like pancreas and salivary glands. The ducts of the sweat glands are also lined by this type epithelium. The stratified cuboidal epithelium has not been found to be involved in absorptive or secretory activity. Its probable function is to provide the ducts with a stronger lining than the simple cuboidal or simple columnar epithelium. Stratified Cuboidal Epithelium Found In: Follicular Antrum Ducts of sweat glands
Read more

SIMPLE COLUMNAR EPITHELIUM

-
Image
Simple Columnar Epithelium This type of epithelium consists of a single layer of columnar (column-shaped cells). On surface view the cells appear as a mosaic resembling that of simple cuboidal epithelium but the outline of the cells is rather smaller. In pendicular sections the columnar shape of the cells becomes evident in which it is seen that the height of each cell is much greater than its width. The nucleus is commonly oval in shape and usually located near the base of the cell. The nuclei of all the cells of a sheet of simple columnar epithelium are often seen to be situated at roughly at the same level. Simple columnar epithelium is widely distributed in the body. Simple Columnar Epithelium   It lines (for example) :  the internal surface of  Stomach  Intestines  Gallbladder  Uterus  In many locations in the body  The cells of the simple columnar epithelium show modifications on their apical surface, which includes microvilli, kinocilia and stereocilia.
Read more

SIMPLE SQUAMOUS EPITHELIUM

-
Image
                The simple squamous epi variety of epithelium consists of a single layer of thin flat cells which are roughly polygonal in outline. The free surface of each flat cell faces a cavity or the lumen of a tubular structure, while the basal surface rests on a basement membrane, The cells have serrated or wavy margins and the adjacent cells fit closely together to form a continuous sheet. Each cell contains a flattened nucleus located in the center of the cell. Presence of the nucleus in the central region of the flat cell causes the plasma membranes above and below to bulge slightly. Simple squamous epithelium                 On surface view the closely fitting polygonal cells appear like a mosaic. Sections made perpendicular to the epithelial sheet show that in profile (ie, in side view) the individual cells give fusiform (spindle-shaped) appearance because the central region of each cell is thicker (due to the presence of the nucleus), while peripherally the cytop
Read more