What are the differences between different types of simple epithelium?

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Simple Squamous Epithelium is composed of a single layer of flattened squamous cells with irregular margins. It is also known as pavement epithelium because the arrangement of cells resemble tiles placed on a floor. The cells are flat and thin enough to allow diffusion of various molecules. Simple squamous epithelium is found in the linings of the cardiovascular and lymphatic systems, capillary walls, buccal and nasal cavity, and alveolar lining of the lungs. The main functions of the simple squamous epithelium include protection, diffusion, absorption, and filtration. 
Simple Cuboidal Epithelium is made up of a single layer of tightly packed cells that look cuboidal in shape. A spherical nucleus is present in the center of each cell. Simple cuboidal epithelium is found in the lining of the stomach, small intestine, and female reproductive tract, salivary glands, pancreas, and in the collecting ducts of the kidneys. They play a pivotal role in absorption and secretion. Special features may help certain types of simple cuboidal epithelia perform their jobs more efficiently. For example, microvilli present in the small intestine increase the surface absorption area. 
Simple Columnar Epithelium is composed of elongated, column-shaped cells that have a longer length compared to their width. The nuclei are also elongated and generally located toward the base of the columnar cells. Simple columnar epithelium is found in the ears, nose, taste buds of the tongue, and linking of the stomach and intestines. The columnar cells in the nose, ears, and taste buds are specialized for sensory reception. The main functions of the simple columnar epithelium include secretion and absorption. 
Pseudostratified Epithelium is made up of a single layer of columnar epithelial cells with nuclei appearing at varying heights, which gives the illusion that the epithelium is stratified or multi-layered. When viewed in cross section it can be determined that it is in fact made up of a single layer. Pseudostratified epithelium is found in lining of the respiratory and urinary tracts, uterus and fallopian tubes in females, vas deferens, and epididymis. It often possesses cilia, which are fine hair-like extensions of their apical membrane.

What are the differences between different types of simple epithelium?

Posted September 26, 2023