The diverticulum is believed to be induced by a combination of several pathways, mainly the Wnt/B-catenin pathway and fibroblast growth factors (FGF), which are secreted by fetal cardiac cells, which is induced by the MAPK pathway. The umbilical vein passes through the falciform ligament on its way from the umbilical cord to the liver. It forms within the peritoneum and is anchored to the abdominal wall by the falciform ligament which arises from the ventral mesentery. It stems from endodermal cells and starts as the hepatic diverticulum around the fourth week of development. The liver arises as a part of the foregut. In the right setting, they can also serve as myofibroblasts and aid in the regeneration of the liver. The Ito cells serve as storage for fat, such as vitamin A. The Kupffer cells sit in the space to filter out unnecessary or pathologic material from the circulation. The space of Disse also contains Kupffer cells (macrophages) and Ito cells (stellate cells). The importance of the scaffolding that takes place in the space of Disse is amplified further by the fact that hepatocytes do not contain a true basement membrane. The space of Disse houses an extracellular matrix composed of a variety of collagens, proteoglycans, and other proteins that help provide scaffolding for the hepatocytes and, by extension, the lobule as a whole. This space is occupied by microvilli extending from the basolateral membrane of the hepatocytes that communicate with the capillary, allowing the hepatocyte to reach its' blood supply. The space between the sinusoidal lumen and the surrounding basolateral membrane of hepatocytes is called the space of Disse. Blood drains into the branch of the hepatic vein that lies in the lobule's center via sinusoidal lumens of the lobule. This makes sense as the liver produces bile, so bile in the ducts are leaving the liver whereas, the dual blood supply is entering the liver to perfuse it. It is important to recognize that bile and blood flow in opposite directions to each other. Due to the 3-dimensional arrangements of hepatocytes, the canaliculi form a lattice-like network or “chicken-wire pattern,” that helps increase the surface area of flow. It plays the largest role in detoxification, biotransformation of drugs, ketogenesis, glycolysis, lipogenesis, glycogen synthesis, and glutamine formation.īile flow is further facilitated by bile canaliculi, which are formed by apical membranes of neighboring hepatocytes. Zone III has the lowest perfusion due to its distance from the portal triad.

Meld into stone long rest