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Splenic
The spleen (, from Ancient Greek '' σπλήν'', splḗn) is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The spleen plays important roles in regard to red blood cells (erythrocytes) and the immune system. It removes old red blood cells and holds a reserve of blood, which can be valuable in case of hemorrhagic shock, and also recycles iron. As a part of the mononuclear phagocyte system, it metabolizes hemoglobin removed from senescent red blood cells. The globin portion of hemoglobin is degraded to its constitutive amino acids, and the heme portion is metabolized to bilirubin, which is removed in the liver. The spleen houses antibody-producing lymphocytes in its white pulp and monocytes which remove antibody-coated bacteria and antibody-coated blood cells by way of blood and lymph node circulation. These monocytes, upon moving to injured tissue (such as the heart after myocardial infarction), turn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Splenic Artery
In human anatomy, the splenic artery or lienal artery, an older term, is the blood vessel that supplies oxygenated blood to the spleen. It branches from the celiac artery, and follows a course superior to the pancreas. It is known for its tortuous path to the spleen. Structure The splenic artery, the largest branch of the celiac trunk, gives off branches to the stomach and pancreas before reaching the spleen. Note that the branches of the splenic artery do not reach all the way to the lower part of the greater curvature of the stomach. Instead, that region is supplied by the right gastroepiploic artery, a branch of the gastroduodenal artery. The two gastroepiploic arteries anastomose with each other at that point. Relations The splenic artery passes between the layers of the lienorenal ligament. Along its course, it is accompanied by a similarly named vein, the splenic vein, which drains into the hepatic portal vein. Clinical significance Splenic artery aneurysms are rare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Splenic Vein
In human anatomy, the splenic vein (formerly the lienal vein) is a blood vessel that drains blood from the spleen, the stomach fundus and part of the pancreas. It is part of the hepatic portal system. Structure The splenic vein is formed from small venules that leave the spleen. It travels above the pancreas, alongside the splenic artery. It collects branches from the stomach and pancreas, and most notably from the large intestine (also drained by the superior mesenteric vein) via the inferior mesenteric vein, which drains in the splenic vein shortly before the origin of the hepatic portal vein. The splenic vein ends in the portal vein, formed when the splenic vein joins the superior mesenteric vein. Clinical significance The splenic vein can be affected by thrombosis, presenting some of the characteristics of portal vein thrombosis and portal hypertension but localized to part of the territory drained by the splenic vein. These include varices in the stomach wall due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Pulp
White pulp is a histological designation for regions of the spleen (named because it appears whiter than the surrounding red pulp on cross section), that encompasses approximately 25% of splenic tissue. White pulp consists entirely of lymphoid tissue. Specifically, the white pulp encompasses several areas with distinct functions: * The periarteriolar lymphoid sheaths (PALS) are typically associated with the arteriole supply of the spleen; they contain T lymphocytes. * Lymph follicles with dividing B lymphocytes are located between the PALS and the marginal zone bordering on the red pulp. IgM and IgG2 are produced in this zone. These molecules play a role in opsonization of extracellular organisms, encapsulated bacteria in particular. * The marginal zone exists between the white pulp and red pulp. It is located farther away from the central arteriole, in proximity to the red pulp. It contains antigen-presenting cells (APCs), such as dendritic cells and macrophages. Some o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphatic System
The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lymphatic tissue and lymph. Lymph is a clear fluid carried by the lymphatic vessels back to the heart for re-circulation. The Latin word for lymph, , refers to the deity of fresh water, "Lympha". Unlike the circulatory system that is a closed system, the lymphatic system is open. The human circulatory system processes an average of 20 litres of blood per day through Starling equation, capillary filtration, which removes blood plasma, plasma from the blood. Roughly 17 litres of the filtered blood is reabsorbed directly into the blood vessels, while the remaining three litres are left in the interstitial fluid. One of the main functions of the lymphatic system is to provide an accessory return route to the blood for the surplus three litres. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Splenic Plexus
The splenic plexus (lienal plexus in older texts) is formed by branches from the celiac plexus, the left celiac ganglion, and from the right vagus nerve. It accompanies the lienal artery to the spleen The spleen (, from Ancient Greek '' σπλήν'', splḗn) is an organ (biology), organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The spleen plays important roles in reg ..., giving off, in its course, subsidiary plexuses along the various branches of the artery. References External links {{Authority control Nerve plexus Nerves of the torso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage
Macrophages (; abbreviated MPhi, φ, MΦ or MP) are a type of white blood cell of the innate immune system that engulf and digest pathogens, such as cancer cells, microbes, cellular debris and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. This self-protection method can be contrasted with that employed by Natural killer cell, Natural Killer cells. This process of engulfment and digestion is called phagocytosis; it acts to defend the host against infection and injury. Macrophages are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement. They take various forms (with various names) throughout the body (e.g., histiocytes, Kupffer cells, alveolar macrophages, microglia, and others), but all are part of the mononuclear phagocyte system. Besides phagocytosis, they play a critical role in nonspecific defense (innate immunity) and also help initiate specific defense mechanisms (adapti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendritic Cell
A dendritic cell (DC) is an antigen-presenting cell (also known as an ''accessory cell'') of the mammalian immune system. A DC's main function is to process antigen material and present it on the cell surface to the T cells of the immune system. They act as messengers between the innate and adaptive immune systems. Dendritic cells are present in tissues that are in contact with the body's external environment, such as the skin, and the inner lining of the nose, lungs, stomach and intestines. They can also be found in an immature and mature state in the blood. Once activated, they migrate to the lymph nodes, where they interact with T cells and B cells to initiate and shape the adaptive immune response. At certain development stages they grow branched projections, the '' dendrites,'' that give the cell its name (δένδρον or déndron being Greek for 'tree'). While similar in appearance to the dendrites of neurons, these are structures distinct from them. Immature dendr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heme
Heme (American English), or haem (Commonwealth English, both pronounced /Help:IPA/English, hi:m/ ), is a ring-shaped iron-containing molecule that commonly serves as a Ligand (biochemistry), ligand of various proteins, more notably as a Prosthetic group, component of hemoglobin, which is necessary to bind oxygen in the bloodstream. It is composed of four pyrrole rings with 2 Vinyl group, vinyl and 2 propionic acid side chains. Heme is biosynthesized in both the bone marrow and the liver. Heme plays a critical role in multiple different redox reactions in mammals, due to its ability to carry the oxygen molecule. Reactions include oxidative metabolism (cytochrome c oxidase, succinate dehydrogenase), xenobiotic detoxification via cytochrome P450 pathways (including Drug metabolism, metabolism of some drugs), gas sensing (Guanylate cyclase, guanyl cyclases, nitric oxide synthase), and microRNA processing (DGCR8). Heme is a coordination complex "consisting of an iron ion coordinated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilirubin
Bilirubin (BR) (adopted from German, originally bili—bile—plus ruber—red—from Latin) is a red-orange compound that occurs in the normcomponent of the straw-yellow color in urine. Another breakdown product, stercobilin, causes the brown color of feces. Although bilirubin is usually found in animals rather than plants, at least one plant species, '' Strelitzia nicolai'', is known to contain the pigment. Structure Bilirubin consists of an open-chain tetrapyrrole. It is formed by oxidative cleavage of a porphyrin in heme, which affords biliverdin. Biliverdin is reduced to bilirubin. After conjugation with glucuronic acid, bilirubin is water-soluble and can be excreted. Bilirubin is structurally similar to the pigment phycobilin used by certain algae to capture light energy, and to the pigment phytochrome used by plants to sense light. All of these contain an open chain of four pyrrolic rings. Like these other pigments, some of the double-bonds in bilirubin isomer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of various proteins and various other Biochemistry, biochemicals necessary for digestion and growth. In humans, it is located in the quadrants and regions of abdomen, right upper quadrant of the abdomen, below the thoracic diaphragm, diaphragm and mostly shielded by the lower right rib cage. Its other metabolic roles include carbohydrate metabolism, the production of a number of hormones, conversion and storage of nutrients such as glucose and glycogen, and the decomposition of red blood cells. Anatomical and medical terminology often use the prefix List of medical roots, suffixes and prefixes#H, ''hepat-'' from ἡπατο-, from the Greek language, Greek word for liver, such as hepatology, and hepatitis The liver is also an accessory digestive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibody
An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as pathogenic bacteria, bacteria and viruses, including those that cause disease. Each individual antibody recognizes one or more specific antigens, and antigens of virtually any size and chemical composition can be recognized. Antigen literally means "antibody generator", as it is the presence of an antigen that drives the formation of an antigen-specific antibody. Each of the branching chains comprising the "Y" of an antibody contains a paratope that specifically binds to one particular epitope on an antigen, allowing the two molecules to bind together with precision. Using this mechanism, antibodies can effectively "tag" the antigen (or a microbe or an infected cell bearing such an antigen) for attack by cells of the immune system, or can neutralize it directly (for example, by blocking a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System
The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic worms, and also objects such as wood splinters, distinguishing them from the organism's own healthy biological tissue, tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use humoral immunity, molecules and cell-mediated immunity, cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against bacteriophage, viral infections. Other basic immune mechanisms evolved in ancien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
