China
Africa
Explore chapters and articles related to this topic
Toxic Responses of the Liver
Published in Stephen K. Hall, Joana Chakraborty, Randall J. Ruch, Chemical Exposure and Toxic Responses, 2020
In the human, the liver resides principally on the right side of the abdomen just below the diaphragm. The liver receives blood from two sources, the hepatic artery and the portal vein. The hepatic artery contains highly oxygenated blood from the lungs and foreign chemicals absorbed into the blood through the lungs, skin, and other routes. The portal vein carries less oxygenated, nutrient-rich blood from the stomach and intestines. Blood exits the liver via the hepatic vein. The portal blood contains nutrients, vitamins, and foreign compounds absorbed through the stomach and intestines. Thus, the liver is the first organ to encounter potentially toxic chemicals ingested orally as well as those entering the blood via other pathways. The liver has well-developed detoxification mechanisms and is very efficient at detoxifying and excreting many chemical agents. However, when a chemical agent is incapable of being detoxified or its levels overwhelm the detoxification capacity of the liver, hepatotoxicity will result.
Elements of Continuum Mechanics
Published in Clement Kleinstreuer, Biofluid Dynamics, 2016
Apart from a patch where it is connected to the diaphragm, the liver is covered entirely by a thin, double-layered membrane that reduces friction against other organs. Based on surface appearance, it can be divided into major folded lobes (see Fig. 4.3.1a). Surprisingly, there are only two types of cells forming the structure of the liver. The liver cells, called hepatocytes, form hepatic plates that are one to two cell-layers thick. These plates are separated by microchannels, called sinusoids (see Fig. 4.3.1b). The channel walls are lined with Kupffer cells which, like white blood cells, can “devour” toxins, bacteria, etc. As indicated in Fig. 4.3.1a, nutrients in the blood from the digestive system are carried via the hepatic partial vein to capillaries in the liver, as it receives arterial blood via the hepatic artery. The hepatic plates are arranged into active units called liver lobules, each with a central vein which collects the arterial/venous blood mixture flowing through the sinusoids (Fig. 4.3.1b). The central veins of all the lobules converge and deliver the blood to the inferior vena cava. In contrast, bile is produced by the hepatocytes and secreted into microchannels, called bile canaliculi, which empty into the bile duct (see Fig. 4.3.1).
Applications in Biology
Published in Gabriel A. Wainer, Discrete-Event Modeling and Simulation, 2017
In terms of its basic anatomy, the liver consists of two wedge-shaped lobes. Two blood vessels enter the liver: the portal vein and the hepatic artery. The portal vein carries dissolved food substances from the small intestine, and the hepatic artery carries oxygenated blood from the lungs. Each lobe is further divided into many small lobules; each is about the size of a pinhead and consists of many liver cells, with bile and blood channels between them.
A fully coupled porous media and channels flow approach for simulation of blood and bile flow through the liver lobules
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
The liver, as the largest endocrine gland, has many functions and duties in the human body. Among these functions, the liver acts as a refinery producing biochemicals for digestion. One of the liver products is bile, an alkaline compound, that helps to emulsify the lipids in the digestion process. The red blood cells decomposition, glycogen storage regulation, and the hormones production are the other roles of the liver. The liver receives blood from two main vessels, including the hepatic Portal Vein (PV) and Hepatic Artery (HA), as shown in Figure 1(a). These vessels are divided into small capillaries inside the liver. Hepatic portal vein provides de-oxygenated blood, rich in digested nutrients, from the gastrointestinal tract, pancreas, and spleen. This is about 75–80% of the total volume of blood entering the liver (Garcea and Maddern 2009). The remainder is provided through the hepatic artery caring fully oxygenated blood, poor in nutrients, from the aorta to the liver (Garcea and Maddern 2009).