What is the difference between squamous cuboidal and columnar epithelial tissue

This epithelial type is found in the walls of capillaries, linings of the pericardium, and the linings of the alveoli of the lungs. Simple cuboidal epithelium consists of a single layer cells that are as tall as they are wide. The important functions of the simple cuboidal epithelium are secretion and absorption. This epithelial type is found in the small collecting ducts of the kidneys, pancreas, and salivary glands.

Simple columnar epithelium is a single row of tall, closely packed cells, aligned in a row. These cells are found in areas with high secretory function such as the wall of the stomach , or absorptive areas as in small intestine. They possess cellular extensions e.

These are simple columnar epithelial cells whose nuclei appear at different heights, giving the misleading hence pseudo impression that the epithelium is stratified when the cells are viewed in cross section. Pseudostratified epithelium can also possess fine hair-like extensions of their apical luminal membrane called cilia. In this case, the epithelium is described as ciliated pseudostratified epithelium. Ciliated epithelium is found in the airways nose, bronchi , but is also found in the uterus and fallopian tubes of females, where the cilia propel the ovum to the uterus.

Stratified epithelium differs from simple epithelium by being multilayered. It is therefore found where body linings have to withstand mechanical or chemical insults. Stratified epithelia are more durable and protection is one their major functions. Since stratified epithelium consists of two or more layers, the basal cells divide and push towards the apex, and in the process flatten the apical cells. The cells are wider in squamous epithelium.

On the other hand, cells are taller in the columnar epithelium. Simple squamous and stratified squamous are the two types of squamous epithelium. Simple columnar, stratified columnar and pseudostratified columnar are the three types of columnar epithelium.

The below infographic shows the difference between squamous epithelium and columnar epithelium in tabular form. Squamous and columnar epithelium are two types of epithelial tissues. Squamous epithelium has cells that are wider than they are tall. Columnar epithelium has cells taller than they are wide. Squamous epithelium has two types while columnar epithelium has three types.

This is the difference between squamous epithelium and columnar epithelium. Available here 2. Available here. Samanthi Udayangani holds a B.

Nuclei of the squamous epithelium are centrally located while the nuclei of the columnar epithelium are mainly located at the bottom. Further difference between squamous epithelium and columnar epithelium is the cilia. Squamous epithelium does not contain cilia while columnar epithelium except stratified columnar epithelium contains cilia. Moreover, the squamous epithelium mainly occurs in the passages that open to the external environment while the columnar epithelium mainly occurs in the inner body surfaces.

Also, functionally too, there are differences between squamous epithelium and columnar epithelium. Squamous epithelium does not perform a secretory function while columnar epithelium secretes mucus and enzymes. Squamous epithelium allows molecules to pass through diffusion while columnar epithelium moves the mucus out of the body.

Squamous epithelium contains flat cells that allow the movement of molecules across it. Columnar epithelium contains column-like cells that allow the secretion of mucus and the movement of mucus by the movement of cilia. There is an exposed edge of epithelial tissue known as the apical surface and an anchoring layer called the basal surface that attaches the epithelial tissue to the underlying connective tissue.

The attachment to connective tissue is known as the basement membrane and is composed of proteins. Epithelial tissues are nearly completely avascular. For instance, no blood vessels cross the basement membrane to enter the tissue, and nutrients must come by diffusion or absorption from underlying tissues or the surface. Many epithelial tissues are capable of rapidly replacing damaged and dead cells.

Sloughing off of damaged or dead cells is a characteristic of surface epithelium and allows our airways and digestive tracts to rapidly replace damaged cells with new cells.

The cells of an epithelium act as gatekeepers of the body controlling permeability and allowing selective transfer of materials across a physical barrier. All substances that enter the body must cross an epithelium.

Some epithelia often include structural features that allow the selective transport of molecules and ions across their cell membranes. Many epithelial cells are capable of secretion and release mucous and specific chemical compounds onto their apical surfaces.

The epithelium of the small intestine releases digestive enzymes, for example. Cells lining the respiratory tract secrete mucous that traps incoming microorganisms and particles. A glandular epithelium contains many secretory cells. Epithelial cells are typically characterized by the polarized distribution of organelles and membrane-bound proteins between their basal and apical surfaces. Particular structures found in some epithelial cells are an adaptation to specific functions.

Certain organelles are segregated to the basal sides, whereas other organelles and extensions, such as cilia, when present, are on the apical surface. Cilia are microscopic extensions of the apical cell membrane that are supported by microtubules. They beat in unison and move fluids as well as trapped particles.

Ciliated epithelium lines the ventricles of the brain where it helps circulate the cerebrospinal fluid. The ciliated epithelium of your airway forms a mucociliary escalator that sweeps particles of dust and pathogens trapped in the secreted mucous toward the throat.

It is called an escalator because it continuously pushes mucous with trapped particles upward. In contrast, nasal cilia sweep the mucous blanket down towards your throat. In both cases, the transported materials are usually swallowed, and end up in the acidic environment of your stomach.