Lobules of liverIn histology (microscopic anatomy), the lobules of liver, or hepatic lobules, are small divisions of the liver defined at the microscopic scale. The hepatic lobule is a building block of the liver tissue, consisting of a portal triad, hepatocytes arranged in linear cords between a capillary network, and a central vein. Lobules are different from the lobes of liver: they are the smaller divisions of the lobes. The two-dimensional microarchitecture of the liver can be viewed from different perspectives: The term "hepatic lobule", without qualification, typically refers to the classical lobule.
Fatty liver diseaseFatty liver disease (FLD), also known as hepatic steatosis, is a condition where excess fat builds up in the liver. Often there are no or few symptoms. Occasionally there may be tiredness or pain in the upper right side of the abdomen. Complications may include cirrhosis, liver cancer, and esophageal varices. There are two types of fatty liver disease: non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease. NAFLD is made up of simple fatty liver and non-alcoholic steatohepatitis (NASH).
Liver diseaseLiver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common. File:Ground glass hepatocytes high mag cropped 2.jpg|Ground glass hepatocytes File:Primary biliary cirrhosis intermed mag much cropping.jpg|Primary biliary cirrhosis File:Buddchiari2.PNG|Budd-chiari syndrome File:Non-alcoholic_fatty_liver_disease1.
Drug metabolismDrug metabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems. More generally, xenobiotic metabolism (from the Greek xenos "stranger" and biotic "related to living beings") is the set of metabolic pathways that modify the chemical structure of xenobiotics, which are compounds foreign to an organism's normal biochemistry, such as any drug or poison. These pathways are a form of biotransformation present in all major groups of organisms and are considered to be of ancient origin.
MitochondrionA mitochondrion (ˌmaɪtəˈkɒndriən; : mitochondria) is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term mitochondrion was coined by Carl Benda in 1898.
CirrhosisCirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage to the liver leads to repair of liver tissue and subsequent formation of scar tissue. Over time, scar tissue can replace normal functioning tissue, leading to the impaired liver function of cirrhosis. The disease typically develops slowly over months or years.
Lipid metabolismLipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown and storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes. In animals, these fats are obtained from food and are synthesized by the liver. Lipogenesis is the process of synthesizing these fats. The majority of lipids found in the human body from ingesting food are triglycerides and cholesterol.
Inner mitochondrial membraneThe inner mitochondrial membrane (IMM) is the mitochondrial membrane which separates the mitochondrial matrix from the intermembrane space. The structure of the inner mitochondrial membrane is extensively folded and compartmentalized. The numerous invaginations of the membrane are called cristae, separated by crista junctions from the inner boundary membrane juxtaposed to the outer membrane. Cristae significantly increase the total membrane surface area compared to a smooth inner membrane and thereby the available working space for oxidative phosphorylation.
Cellular respirationCellular respiration is the process by which biological fuels are oxidised in the presence of an inorganic electron acceptor, such as oxygen, to drive the bulk production of adenosine triphosphate (ATP), which contains energy. Cellular respiration may be described as a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from nutrients into ATP, and then release waste products.
Flux (metabolism)Flux, or metabolic flux is the rate of turnover of molecules through a metabolic pathway. Flux is regulated by the enzymes involved in a pathway. Within cells, regulation of flux is vital for all metabolic pathways to regulate the pathway's activity under different conditions. Flux is therefore of great interest in metabolic network modelling, where it is analysed via flux balance analysis and metabolic control analysis.
Mitochondrial DNAMitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced.
Mitochondrial matrixIn the mitochondrion, the matrix is the space within the inner membrane. The word "matrix" stems from the fact that this space is viscous, compared to the relatively aqueous cytoplasm. The mitochondrial matrix contains the mitochondrial DNA, ribosomes, soluble enzymes, small organic molecules, nucleotide cofactors, and inorganic ions.[1] The enzymes in the matrix facilitate reactions responsible for the production of ATP, such as the citric acid cycle, oxidative phosphorylation, oxidation of pyruvate, and the beta oxidation of fatty acids.
LiverThe liver is a major metabolic organ only found in vertebrate animals, which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it is located in the right upper quadrant of the abdomen, below the diaphragm and mostly shielded by the lower right rib cage. Its other metabolic roles include carbohydrate metabolism, the production of hormones, conversion and storage of nutrients such as glucose and glycogen, and the decomposition of red blood cells.
Carbohydrate metabolismCarbohydrate metabolism is the whole of the biochemical processes responsible for the metabolic formation, breakdown, and interconversion of carbohydrates in living organisms. Carbohydrates are central to many essential metabolic pathways. Plants synthesize carbohydrates from carbon dioxide and water through photosynthesis, allowing them to store energy absorbed from sunlight internally. When animals and fungi consume plants, they use cellular respiration to break down these stored carbohydrates to make energy available to cells.
Non-alcoholic fatty liver diseaseMetabolic (dysfunction) associated fatty liver disease (MAFLD) was previously known as non-alcoholic fatty liver disease (NAFLD) until renamed in 2023 by a global consensus panel composed mostly of hepatology researchers and clinicians. The term metabolic dysfunction-associated steatotic liver disease (MASLD) is also used. MAFLD is excessive fat build-up in the liver without another clear cause such as alcohol use.
Alcoholic liver diseaseAlcoholic liver disease (ALD), also called alcohol-related liver disease (ARLD), is a term that encompasses the liver manifestations of alcohol overconsumption, including fatty liver, alcoholic hepatitis, and chronic hepatitis with liver fibrosis or cirrhosis. It is the major cause of liver disease in Western countries. Although steatosis (fatty liver disease) will develop in any individual who consumes a large quantity of alcoholic beverages over a long period of time, this process is transient and reversible.
MetabolismMetabolism (məˈtæbəlɪzəm, from μεταβολή metabolē, "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments.
HomeostasisIn biology, homeostasis (British also homoeostasis) (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physical, chemical, and social conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium, and calcium ions, as well as the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity.
Liver cancerLiver cancer (also known as hepatic cancer, primary hepatic cancer, or primary hepatic malignancy) is cancer that starts in the liver. Liver cancer can be primary (starts in liver) or secondary (meaning cancer which has spread from elsewhere to the liver, known as liver metastasis). Liver metastasis is more common than that which starts in the liver. Liver cancer is increasing globally. Primary liver cancer is globally the sixth-most frequent cancer and the fourth-leading cause of death from cancer.
Chronic liver diseaseChronic liver disease in the clinical context is a disease process of the liver that involves a process of progressive destruction and regeneration of the liver parenchyma leading to fibrosis and cirrhosis. "Chronic liver disease" refers to disease of the liver which lasts over a period of six months. It consists of a wide range of liver pathologies which include inflammation (chronic hepatitis), liver cirrhosis, and hepatocellular carcinoma. The entire spectrum need not be experienced.
