Hepatic-Portal Circulation Physiology Explained скачать в хорошем качестве

Hepatic-Portal Circulation Physiology Explained

The porta hepatis contains the hepatic artery, the hepatic portal vein, and the common hepatic duct. The hepatic artery delivers oxygen-rich arterial blood from the heart to the liver, while the hepatic portal vein delivers nutrient-rich venous blood from the gastrointestinal tract, but also from the spleen, and pancreas. Lastly, the common hepatic duct drains bile from the liver into the gallbladder. Now let’s take a closer look inside a section of the liver, which shows the functional units of the liver called hepatic lobules. Each hepatic lobule looks like a tiny hexagon. At the periphery of the hepatic lobule, there are portal triads which are made up of a branch of the hepatic artery, a branch of the portal vein and one or two small bile ducts. Now, these branches of the hepatic artery and the portal vein both drain into very porous blood vessels called sinusoids which carry blood towards the center of the lobule and drain into the central vein. From central veins, the blood flows into the hepatic veins and eventually drain into the inferior vena cava. Portal hypertension means increased blood pressure in the hepatic portal system - or portal venous system. Most commonly, this happens because of hepatic cirrhosis, which is when the liver tissue is replaced by fibrotic, functionless tissue. Now, the portal venous system comprises the portal vein and its tributaries - namely, the splenic, and mesenteric veins. This blood contains all the nutrients absorbed in the GI tract, but it also carries toxins that the liver metabolizes so that they can be safely excreted by the kidneys. Once the liver processes all these substances, it sends the blood to the heart, through the inferior vena cava, to enter the systemic venous system. Now, there’s a few points in the boundaries of the hepatic portal system, where it could be connected with the systemic venous system that collects blood from the rest of the body: the inferior portion of the esophagus, the superior portion of the anal canal, and the round ligament of the liver - which used to be the umbilical vein during fetal life. Join this our membership section to get access to perks:    / @medcrine   SUBSCRIBE, LIKE and SHARE Check our website for more medical lecture notes at https://medcrine.com Follow us on twitter @medcrine Facebook at www.fb.me/medcrine Pinterest at pinterest.com/medcrine Telegram at t.me/medcrine email us on [email protected]