endotelijsko

Endothelium, also known as endothelia, is a layer of cells that lines the interior surface of all blood vessels and lymphatic vessels, as well as the heart, lungs, and serous cavities of the body. It plays a crucial role in maintaining the integrity and function of these vessels and organs. The endothelium is composed of a single layer of squamous cells that are tightly joined together, forming a continuous barrier that prevents the leakage of blood and other fluids into the surrounding tissues.

The endothelium has several important functions. It regulates the exchange of substances between the blood and the surrounding tissues, allowing for the diffusion of oxygen, nutrients, and waste products. It also plays a role in the immune response, as it can produce and release various cytokines and chemokines that help to recruit immune cells to sites of infection or injury. Additionally, the endothelium is involved in the regulation of blood pressure and vascular tone, as it can contract or relax in response to various stimuli.

The endothelium is also a target for various diseases, including atherosclerosis, hypertension, and inflammation. In atherosclerosis, for example, the endothelium becomes damaged, leading to the accumulation of lipid deposits and the formation of plaques, which can eventually occlude the vessel and lead to a heart attack or stroke. In hypertension, the endothelium becomes dysfunctional, leading to increased vascular resistance and elevated blood pressure.

Despite its importance, the endothelium is relatively inaccessible for direct study, as it is located deep within the body and is surrounded by other layers of tissue. However, recent advances in imaging and molecular biology techniques have allowed researchers to gain a better understanding of the endothelium's structure and function, and to develop new therapies for diseases that affect this vital tissue.