Transitional Epithelium

What Is Transitional Epithelium?

Transitional epithelium, one of the kinds of stratified epithelium, forms multiple layers of cells that look cuboidal if not under tension and squamous when stretched, showing characteristics of stretchiness and change of shape. The type of epithelium can provide possibilities of change in volume and pressure inside lining organs.

Transitional epithelium plays a critical role in the urinary system. Lining the inner surface of the urinary bladder, the ureters, and part of the urethra, enables these organs to stretch without rupturing when they fill and again when they empty. Since it is elastic, it does not allow for the diffusion of urine into underlying tissues; hence, the integrity of the urinary tract is maintained while it undergoes volume changes. It is therefore important to both fluid retention and elimination.

Structure Of Transitional Epithelium

The structure of transitional epithelium is described below-

Description Of Cells And Their Arrangement

The transitional epithelium consists of several layers of cells. Peripheral cells are large and dome-shaped. As one goes toward the basal layer, the cells decrease in size and become cuboidal or columnar.

Unique features

Ability for stretching and change of shape: Probably one of the most distinct features of transitional epithelium is its ability to stretch and change shape. This allows organs like the bladder to dilate and contract without tearing.

Comparison With Other Epithelial Types

While this epithelium stands in contrast to simple squamous or cuboidal epithelium, it can increase its volume. It is firmer and more elastic than any other epithelial tissue, most of which are stiff/rigid.

Location In The Human Body

The location of transitional epithelium is described below-

Location

Transitional epithelium will be lining the inside of the urinary bladder, ureters, and part of the urethra.

Role In These Organs

This kind of epithelium lining gives a protective covering, whereby leakage is not possible, hence saving the underlying tissues from damage by the urine in these organs.

Functions Of Transitional Epithelium

The functions of transitional epithelium are described below-

Protection

Lining and forming a protective covering, saves underlying tissues from the corrosive action of urine.

Distending And Expanding Ability

This elasticity feature enables organs like the urinary bladder to distend to a large volume at times when it is full of urine and contract when empty.

Barrier Function To Avoid Urine Leakage

The tight junctions seal the cells together and hence act as a barrier to prevent leakage of urine in the surrounding tissues.

Recommended video on "Transitional Epithelium"