part of part of endothelial cell fenestrated endothelial cell endothelial cell of sinusoid endothelial cell of hepatic sinusoid https://cdn.humanatlas.io/digital-objects/2d-ftu/liver-liver-lobule/v1.3/assets/2d-ftu-liver-liver-lobule.png endotheliocyte of hepatic sinusoid An endothelial cell that is part of the hepatic sinusoid. These cells possess flattened areas containing perforations about 0.1 micrometers in diameter, known as fenestrae. The fenestrae are arranged in groups known as sieve plates. Endothelial cells of hepatic sinusoids, also known as hepatic or liver sinusoidal endothelial cells (HSEC or LSEC), are unique, specialized type of endothelial cells located in the liver. They are the building units of the hepatic sinusoid, which functions as a specialized capillary system that facilitates the exchange of various substances between the blood and hepatocytes. This finely tuned environment, facilitated by HSEC, is primordial for the liver's multiple physiologic functions that include nutrient metabolism, toxin inactivation, and immunomodulation. The HSEC have a distinctive morphology that sets them apart from the typical endothelial cells found in other organs. These cells are exceptionally thin to allow for efficient transfer of molecules and characterized by fenestrations, which are non-diaphragmatic, sieve-like openings that provide an open filtration pathway from the sinusoidal lumen to the space of Disse, where hepatocytes are exposed. The fenestration is a crucial feature that allows lipoproteins, nutrients, and other plasma components easy access to hepatocytes for essential liver functions, including clearance of waste products and metabolic regulation. HSECs further play a vital role in immune functionality in the liver. They act as a sentinel, determining the nature of the immune response to encountered particulates. They possess a capacity for antigen presentation and express a series of immune-related surface molecules, which helps in immunosurveillance and immunoregulation. The HSEC also aid in the removal and destruction of virus-infected cells, harmful microorganisms, and circulatory waste products to safeguard liver health and general systemic cleanliness. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) liver sinusoidal endothelial cell BTO:000125 LSEC https://cellxgene.cziscience.com/cellguide/CL_1000398 FMA:62911 Homo sapiens hepatic sinusoid