Overgangsepiteeli

Overgangsepiteeli, also known as transitional epithelium, is a type of epithelial tissue characterized by cells that can change shape and function depending on the demands placed upon them. This tissue is found in areas of the body where there is a need for flexibility and adaptability, such as the urinary bladder, ureters, and parts of the male urethra. The cells of transitional epithelium are typically polygonal or cuboidal when the tissue is stretched, but can become flattened when the tissue is compressed or distended.

The structure of transitional epithelium is unique due to its ability to stretch and return to its original shape. This is achieved through the presence of specialized junctions between the cells, including tight junctions and desmosomes, which help maintain the integrity of the tissue. The cells also contain numerous mitochondria, which provide the energy needed for the tissue's dynamic changes.

Transitional epithelium is highly vascularized, which allows for efficient nutrient and waste exchange. The tissue is also innervated, meaning it contains nerve endings that can respond to stimuli such as distension or irritation. This sensitivity is important for the body's ability to regulate the function of organs lined with transitional epithelium, such as the bladder.

In addition to its structural and functional properties, transitional epithelium plays a crucial role in the body's defense mechanisms. The tissue can secrete mucus and other protective substances, and it also has the ability to repair itself after injury. This makes it an important component of the body's overall health and well-being.