What is the Origin of Endothelium?

The term is derived from the Greek words endon meaning "within" and thele meaning "nipple" or "membrane," indicating its position as the innermost lining. It is a fundamental anatomical structure in human physiology, recognized for its role as a dynamic, metabolically active organ rather than a passive lining. Endothelial health is a modern focus of longevity medicine.

What is the Mechanism of Endothelium?

The endothelium functions as a crucial endocrine organ, constantly releasing paracrine factors that regulate vascular tone, platelet aggregation, and immune response. Key mediators include nitric oxide, which promotes vasodilation and anti-inflammatory effects, and endothelin, which induces vasoconstriction. Hormones such as estrogen and testosterone directly interact with endothelial receptors, influencing its ability to maintain vascular flexibility and integrity, thereby linking hormonal status to cardiovascular longevity.

Endothelium ∞ Area

Endothelium

Meaning

A single layer of specialized epithelial cells that lines the interior surface of all blood vessels, including arteries, veins, capillaries, and lymphatic vessels. This critical cellular interface acts as a semi-selective barrier between the circulating blood and the vessel wall. Its health is paramount to cardiovascular and metabolic function, directly influencing blood flow and nutrient exchange. Dysfunction in this layer is a recognized precursor to numerous chronic diseases.