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Podocyte
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. Severa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerulus (kidney)
The glomerulus (plural glomeruli) is a network of small blood vessels (capillaries) known as a ''tuft'', located at the beginning of a nephron in the kidney. Each of the two kidneys contains about one million nephrons. The tuft is structurally supported by the mesangium (the space between the blood vessels), composed of intraglomerular mesangial cells. The blood is filtered across the capillary walls of this tuft through the glomerular filtration barrier, which yields its filtrate of water and soluble substances to a cup-like sac known as Bowman's capsule. The filtrate then enters the renal tubule of the nephron. The glomerulus receives its blood supply from an afferent arteriole of the renal arterial circulation. Unlike most capillary beds, the glomerular capillaries exit into efferent arterioles rather than venules. The resistance of the efferent arterioles causes sufficient hydrostatic pressure within the glomerulus to provide the force for ultrafiltration. The glomeru ... [...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 glo ... [...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 glo ... [...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 protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bowman's Capsule
Bowman's capsule (or the Bowman capsule, capsula glomeruli, or glomerular capsule) is a cup-like sac at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine. A glomerulus is enclosed in the sac. Fluids from blood in the glomerulus are collected in the Bowman's capsule. Structure Outside the capsule, there are two "poles": * The vascular pole is the side with the afferent arteriole and efferent arteriole. * The urinary pole is the side with the proximal convoluted tubule. Inside the capsule, the layers are as follows, from outside to inside: *''Parietal layer''—A single layer of simple squamous epithelium. Does not function in filtration. *''Bowman's space (or "urinary space", or "capsular space")''—Between the visceral and parietal layers, into which the filtrate enters after passing through the filtration slits. *''Visceral layer''—Lies just above the thickened glomerular ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renal Corpuscle
A renal corpuscle (also called malpighian body) is the blood-filtering component of the nephron of the kidney. It consists of a glomerulus - a tuft of capillaries composed of endothelial cells, and a glomerular capsule known as Bowman's capsule. Structure The renal corpuscle is composed of two structures, the glomerulus and the Bowman's capsule. The glomerulus is a small tuft of capillaries containing two cell types. Endothelial cells, which have large fenestrae, are not covered by diaphragms. Mesangial cells are modified smooth muscle cells that lie between the capillaries. They regulate blood flow by their contractile activity and secrete extracellular matrix, prostaglandins, and cytokines. Mesangial cells also have phagocytic activity, removing proteins and other molecules trapped in the glomerular basement membrane or filtration barrier. The Bowman's capsule has an outer parietal layer composed of simple squamous epithelium. The visceral layer, composed of modified s ... [...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 migr ... [...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 podoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Process (anatomy)
In anatomy, a process ( la, processus) is a projection or outgrowth of tissue from a larger body. For instance, in a vertebra, a process may serve for muscle attachment and leverage (as in the case of the transverse and spinous processes), or to fit (forming a synovial joint), with another vertebra (as in the case of the articular processes).Moore, Keith L. et al. (2010) ''Clinically Oriented Anatomy'', 6th Ed, p.442 fig. 4.2 The word is used even at the microanatomic level, where cells can have processes such as cilia or pedicels. Depending on the tissue, processes may also be called by other terms, such as ''apophysis'', ''tubercle'', or ''protuberance''. Examples Examples of processes include: *The many processes of the human skull: ** The mastoid and styloid processes of the temporal bone ** The zygomatic process of the temporal bone ** The zygomatic process of the frontal bone ** The orbital, temporal, lateral, frontal, and maxillary processes of the zygomatic bo ... [...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 ... [...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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultrafiltration (kidney)
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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
