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Filtration Slits
Podocytes are cells in Bowman's capsule in the kidneys that wrap around capillaries of the glomerulus. Podocytes make up the epithelial lining of Bowman's capsule, the third layer through which filtration of blood takes place. Bowman's capsule filters the blood, retaining large molecules such as proteins while smaller molecules such as water, salts, and sugars are filtered as the first step in the formation of urine. Although various viscera have epithelial layers, the name visceral epithelial cells usually refers specifically to podocytes, which are specialized epithelial cells that reside in the visceral layer of the capsule. One type of specialized epithelial cell is podocalyxin. The podocytes have long foot processes called ''pedicels'', for which the cells are named (''podo-'' + '' -cyte''). The pedicels wrap around the capillaries and leave slits between them. Blood is filtered through these slits, each known as a filtration slit, slit diaphragm, or slit pore. Several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermediate Mesoderm
Intermediate mesoderm or intermediate mesenchyme is a narrow section of the mesoderm (one of the three primary germ layers) located between the paraxial mesoderm and the lateral plate of the developing embryo. The intermediate mesoderm develops into vital parts of the urogenital system (kidneys, gonads and respective tracts). Early formation Factors regulating the formation of the intermediate mesoderm are not fully understood. It is believed that bone morphogenic proteins, or BMPs, specify regions of growth along the dorsal-ventral axis of the mesoderm and plays a central role in formation of the intermediate mesoderm. Vg1/Nodal signalling is an identified regulator of intermediate mesoderm formation acting through BMP signalling. Excess Vg1/Nodal signalling during early gastrulation stages results in expansion of the intermediate mesoderm at the expense of the adjacent paraxial mesoderm, whereas inhibition of Vg1/Nodal signalling represses intermediate mesoderm formation. A li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Podocalyxin
Podocalyxin, a sialoglycoprotein, is thought to be the major constituent of the glycocalyx of podocytes in the glomerulus (Bowman's capsule) in the kidneys. It is a member of the CD34 family of transmembrane sialomucins. It coats the secondary foot processes of the podocytes. It is negatively charged and thus functions through charge repulsion to keep adjacent foot processes separated, thereby keeping the urinary filtration barrier open. This function is further supported by knockout studies in mice which reveal an essential role in podocyte morphogenesis and a role in the opening of vascular lumens and regulation of vascular permeability. Of note, this is the only cell surface sialomucin knockout known to display a lethal phenotype. Podocalyxin is also upregulated in a number of cancers and is frequently associated with poor prognosis. Podocalyxin is important for us to potentially provide a better understand of cancer development and its aggressiveness through induced cell migra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerular Basement Membrane
The glomerular basement membrane of the kidney is the basal lamina layer of the glomerulus. The glomerular endothelial cells, the glomerular basement membrane, and the filtration slits between the podocytes perform the filtration function of the glomerulus, separating the blood in the capillaries from the filtrate that forms in Bowman's capsule. The glomerular basement membrane is a fusion of the endothelial cell and podocyte basal laminas, and is the main site of restriction of water flow. Glomerular basement membrane is secreted and maintained by podocyte cells. Layers The glomular basement membrane contains three layers: The glomerular membrane consists of mesangial cells, modified pericytes that in other parts of the body separate capillaries from each other. The podocytes adjoining them have filtration slits of diameter 25 nm that are formed by the pseudopodia arising from them. The filtration slits are covered by a diaphragm that includes the transmembrane protein n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultrafiltration (renal)
In renal physiology, ultrafiltration occurs at the barrier between the blood and the filtrate in the glomerular capsule (Bowman's capsule) in the kidneys. As in nonbiological examples of ultrafiltration, pressure (in this case blood pressure) and concentration gradients lead to a separation through a semipermeable membrane (provided by the podocytes). The Bowman's capsule contains a dense capillary network called the glomerulus. Blood flows into these capillaries through the afferent arterioles and leaves through the efferent arterioles. The high hydrostatic pressure forces small molecules in the tubular fluid such as water, glucose, amino acids, sodium chloride and urea through the filter, from the blood in the glomerular capsule across the basement membrane of the Bowman's capsule and into the renal tubules. This process is called ultrafiltration; the resulting fluid, virtually free of large proteins and blood cells, is referred to as glomerular filtrate, or ultrafiltrate. Fur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillaries
A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: they convey blood between the arterioles and venules. These microvessels are the site of exchange of many substances with the interstitial fluid surrounding them. Substances which cross capillaries include water, oxygen, carbon dioxide, urea, glucose, uric acid, lactic acid and creatinine. Lymph capillaries connect with larger lymph vessels to drain lymphatic fluid collected in the microcirculation. During early embryonic development, new capillaries are formed through vasculogenesis, the process of blood vessel formation that occurs through a '' de novo'' production of endothelial cells that then form vascular tubes. The term ''angiogenesis'' denotes the formation of new capillaries from pre-existing blood vessels and already present endo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology Of Nephron
Renal physiology (Latin ''rēnēs'', "kidneys") is the study of the physiology of the kidney. This encompasses all functions of the kidney, including maintenance of acid-base balance; regulation of fluid balance; regulation of sodium, potassium, and other electrolytes; clearance of toxins; absorption of glucose, amino acids, and other small molecules; regulation of blood pressure; production of various hormones, such as erythropoietin; and activation of vitamin D. Much of renal physiology is studied at the level of the nephron, the smallest functional unit of the kidney. Each nephron begins with a filtration component that filters the blood entering the kidney. This filtrate then flows along the length of the nephron, which is a tubular structure lined by a single layer of specialized cells and surrounded by capillaries. The major functions of these lining cells are the reabsorption of water and small molecules from the filtrate into the blood, and the secretion of wastes from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zipper
A zipper, zip, fly, or zip fastener, formerly known as a clasp locker, is a commonly used device for binding together two edges of textile, fabric or other flexible material. Used in clothing (e.g. jackets and jeans), luggage and other Bag, bags, camping gear (e.g. tents and sleeping bags), and many other items, zippers come in a wide range of sizes, shapes, and colors. Whitcomb L. Judson, an American inventor from Chicago, in 1892 patented the original design from which the modern device evolved. Description A zipper consists of a slider mounted on two rows of metal or plastic teeth that are designed to interlock and thereby join the material to which the rows are attached. The slider, usually operated by hand, contains a Y-shaped channel that, by moving along the rows of teeth, meshes or separates them, depending on the direction of the slider's movement. The teeth may be individually discrete or shaped from a continuous coil, and are also referred to as ''elements''. The wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephrin
Nephrin is a protein necessary for the proper functioning of the renal filtration barrier. The renal filtration barrier consists of fenestrated endothelial cells, the glomerular basement membrane, and the podocytes of epithelial cells. Nephrin is a transmembrane protein that is a structural component of the slit diaphragm. They are present on the tips of the podocytes as an intricate mesh and convey strong negative charges which repel protein from crossing into the Bowman's space. A defect in the gene for nephrin, NPHS1, is associated with congenital nephrotic syndrome of the Finnish type and causes massive amounts of protein to be leaked into the urine, or proteinuria. Nephrin is also required for cardiovascular development. Interactions Nephrin has been shown to interact with: * CASK, * CD2AP, * CDH3 and * CTNND1, * FYN, * KIRREL, and * NPHS2. See also * Podocyte Podocytes are cells in Bowman's capsule in the kidneys that wrap around capillaries of the glomerul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidney Failure
Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as either acute kidney failure, which develops rapidly and may resolve; and chronic kidney failure, which develops slowly and can often be irreversible. Symptoms may include leg swelling, feeling tired, vomiting, loss of appetite, and confusion. Complications of acute and chronic failure include uremia, high blood potassium, and volume overload. Complications of chronic failure also include heart disease, high blood pressure, and anemia. Causes of acute kidney failure include low blood pressure, blockage of the urinary tract, certain medications, muscle breakdown, and hemolytic uremic syndrome. Causes of chronic kidney failure include diabetes, high blood pressure, nephrotic syndrome, and polycystic kidney disease. Diagnosis of acute failure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Predisposition
A genetic predisposition is a genetic characteristic which influences the possible phenotypic development of an individual organism within a species or population under the influence of environmental conditions. In medicine, genetic susceptibility to a disease refers to a genetic predisposition to a health problem, which may eventually be triggered by particular environmental or lifestyle factors, such as tobacco smoking or diet. Genetic testing is able to identify individuals who are genetically predisposed to certain diseases. Behavior Predisposition is the capacity humans are born with to learn things such as language and concept of self. Negative environmental influences may block the predisposition (ability) one has to do some things. Behaviors displayed by animals can be influenced by genetic predispositions. Genetic predisposition towards certain human behaviors is scientifically investigated by attempts to identify patterns of human behavior that seem to be invariant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD2AP
CD2-associated protein is a protein that in humans is encoded by the ''CD2AP'' gene. Function This gene encodes a scaffolding molecule that regulates the actin cytoskeleton. The protein directly interacts with filamentous actin and a variety of cell membrane proteins through multiple actin binding sites, SH3 domains, and a proline-rich region containing binding sites for SH3 domains. The cytoplasmic protein localizes to membrane ruffles, lipid rafts, and the leading edges of cells. It is implicated in dynamic actin remodeling and membrane trafficking that occurs during receptor endocytosis and cytokinesis. Haploinsufficiency of this gene is implicated in susceptibility to glomerular disease. Interactions CD2AP has been shown to interact with: * Cbl gene, * NPHS2, * Nephrin, and * RAB4A. See also * Focal segmental glomerulosclerosis Focal segmental glomerulosclerosis (FSGS) is a histopathologic finding of scarring (sclerosis) of glomeruli and damage to renal podocyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephrin
Nephrin is a protein necessary for the proper functioning of the renal filtration barrier. The renal filtration barrier consists of fenestrated endothelial cells, the glomerular basement membrane, and the podocytes of epithelial cells. Nephrin is a transmembrane protein that is a structural component of the slit diaphragm. They are present on the tips of the podocytes as an intricate mesh and convey strong negative charges which repel protein from crossing into the Bowman's space. A defect in the gene for nephrin, NPHS1, is associated with congenital nephrotic syndrome of the Finnish type and causes massive amounts of protein to be leaked into the urine, or proteinuria. Nephrin is also required for cardiovascular development. Interactions Nephrin has been shown to interact with: * CASK, * CD2AP, * CDH3 and * CTNND1, * FYN, * KIRREL, and * NPHS2. See also * Podocyte Podocytes are cells in Bowman's capsule in the kidneys that wrap around capillaries of the glomerul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
