Simple Columnar Epithelium
Simple Columnar Epithelium Definition:
The Simple Columnar Epithelium is tissues composed of a single layer of long epithelial cells which are usually seen in an area where absorption and secretion are important facts. The cells of these epithelial are arranged in a neat row within nuclei at the same level, near to th basal end.
In a cross-section of organs, these cells look like thin columns, which differentiate them from flattened squamous cells and are square-shaped cuboidal cells. This subtype may withstand some degree of wear and tear among simple epithelia.
Types of Simple Columnar Epithelium:
The simple columnar epithelia are tissues that are divided into ciliated or non-ciliated on the basis of the presence of motile cilia. Almost every eukaryotic cell has a single primary non-motile cilium which involves the development and homeostasis. Most of the cells are known as �non-ciliated� in order to distinguish them from structures that move the particles in a specific direction.
The ciliated cells are present in fallopian tubes and endometrium, and involve in ovum movement, while the non-ciliated cells are present in the stomach, small intestine, large intestine, and rectum. These cells usually are seen with �brush border�, the location where the apical surface of plasma covered in minute actin-based projections, known as microvilli.
Functions of Simple Columnar Epithelium:
- The simple columnar epithelia perform the function of secretion and absorption.
- The presence of microvilli on the apical surface used to increase the surface area.
- In the small intestine, these cytoplasmic projections consist of membrane-bound enzymes which used to complete the final stage of digestion.
- Their location of the membrane is near to transmembrane transport proteins which permit the end products of digestion to be fast and immediate absorption in the body.
Example of Simple Columnar Epithelium
The simple columnar epithelia also present in the parts of respiratory, digestive and reproductive tracts, where the mechanical absorption is necessary.
These epithelia also found in the stomach, small and large intestine, where the food transformed largely into homogenous, liquid chyme. In the mouth, stratified epithelia secure the underlying tissues of the esophagus and anus, where textures can vary.
In the respiratory system, the bronchioles are small passageways which are free from cartilage and glands. They create by repeated branching of larger bronchi and they are the part of the system which conducts air towards the site for the exchange of gas.
These terminal bronchioles are lined with the simple columnar epithelia consists of club cells which secrete surfactant. This surfactant is used to prevent the bronchiole and the small structures from collapsing during the expiration and to neutralize the harmful material in the fluid present in the lungs.
The intestinal epithelium is a layer of cells that are lining the small and large intestines. The cells of this epithelium are held with each other with tight junctions that occlude digested food partially from the impenetrable barrier. This epithelium tissue consists of a varied population being created by enterocytes. These cells used to produce many membranes bound digestive enzymes.