What are hepatic sinusoids?
The hepatic sinusoids are specialized vascular structures that, in contrast to other blood vessels, lack a basement membrane, and are instead lined only by fenestrated (porous) endothelial cells (DeLeve et al., 2004).
What happens in hepatic sinusoids?
Hepatic stellate cells are present in the space of Disse and are involved in scar formation in response to liver damage. Defenestration also known as capillarisation happens when LSECs are lost rendering the sinusoid as an ordinary capillary….
Where do hepatic sinusoids receive blood from?
Sinusoids are low pressure vascular channels that receive blood from terminal branches of the hepatic artery and portal vein at the periphery of lobules and deliver it into central veins.
What material flows through the sinusoids of the liver?
In the liver the blood from the portal vein flows through a network of microscopic vessels called sinusoids in which the blood is relieved of worn-out red cells, bacteria, and other debris and in which nutrients are added to the blood or removed from it for storage.…
How does blood flow through a liver lobule?
In the hepatic lobule, blood enters the lobule via the portal vein and hepatic artery, located within portal triads (PT). This venous and arterial blood then combines and drains through hepatic sinusoids towards the central vein (CV). The direction of blood flow is shown as red arrows.
What lies between the basal surface of hepatocytes and the sinusoid epithelium?
The basal surfaces of hepatocytes are flanked by subendothelial sinusoidal spaces (better known as the space of Disse) that allow the access of hepatocytes to the sinusoidal blood flow (Fig.
What is sinusoid in bone marrow?
Venous sinusoids in bone marrow are the site of a large-scale traffic of cells between the extravascular hemopoietic compartment and the blood stream. The wall of the sinusoids consists solely of a basement membrane interposed between a layer of endothelial cells and an incomplete covering of adventitial cells.
What is a sinusoid in medical terms?
sinusoid, irregular tubular space for the passage of blood, taking the place of capillaries and venules in the liver, spleen, and bone marrow. The sinusoids form from branches of the portal vein in the liver and from arterioles (minute arteries) in other organs.
How is blood filtered in the liver?
The blood flows into the liver through the hepatic portal vein. It filters through the liver in a system of smaller and smaller veins. As blood passes over liver cells, these cells process nutrients in the blood. This processing makes products like proteins and sugars that your body can use.
What is the hepatic sinusoid?
The hepatic sinusoid is a unique vascular structure with highly specialized endothelial cells and phagocytic Kupffer cells effacing the blood.
What are the morphological sites for blood flow through the sinusoids?
There are several potential morphological sites for regulating blood flow through the sinusoids. These include the various segments of the afferent portal venules and hepatic arterioles, the sinusoids themselves, and central and hepatic venules.
Why are hepatic arterioles more responsive to sinus pressure?
Hepatic arterioles are more responsive because of a complete investment of smooth muscle and relatively small lumens. The principal site of regulation of blood flow through the sinusoids, however, is thought to reside in the sinusoid itself, where the major blood pressure drop occurs in the liver.
What are the endothelial cells of the hepatic sinusoid?
Endothelial Cells. Endothelial cells of the hepatic sinusoid are flat cells (Figs. 2.6 and 2.8A), forming the lining of the sinusoidal wall. Their thin, flat processes of cytoplasm are spread out and contain fenestrae, clustered in groups to form sieve plates.