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Renal Physiology
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renal Diuretics
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood exits into the paired renal veins. Each kidney is attached to a ureter, a tube that carries excreted urine to the bladder. The kidney participates in the control of the volume of various body fluids, fluid osmolality, acid–base balance, various electrolyte concentrations, and removal of toxins. Filtration occurs in the glomerulus: one-fifth of the blood volume that enters the kidneys is filtered. Examples of substances reabsorbed are solute-free water, sodium, bicarbonate, glucose, and amino acids. Examples of substances secreted are hydrogen, ammonium, potassium and uric acid. The nephron is the structural and functional unit of the kidney. Each adult human kidney contains around 1 million nephrons, while a mouse kidney contains only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephron
The nephron is the minute or microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and a cup-shaped structure called Bowman's capsule. The renal tubule extends from the capsule. The capsule and tubule are connected and are composed of epithelial cells with a lumen. A healthy adult has 1 to 1.5 million nephrons in each kidney. Blood is filtered as it passes through three layers: the endothelial cells of the capillary wall, its basement membrane, and between the foot processes of the podocytes of the lining of the capsule. The tubule has adjacent peritubular capillaries that run between the descending and ascending portions of the tubule. As the fluid from the capsule flows down into the tubule, it is processed by the epithelial cells lining the tubule: water is reabsorbed and substances are exchanged (some are added, others are removed); first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Word Sense
In linguistics, a word sense is one of the meanings of a word. For example, a dictionary may have over 50 different senses of the word " play", each of these having a different meaning based on the context of the word's usage in a sentence, as follows: In each sentence different collocates of "play" signal its different meanings. People and computers, as they read words, must use a process called word-sense disambiguationR. Navigli''Word Sense Disambiguation: A Survey', ACM Computing Surveys, 41(2), 2009, pp. 1-69. to reconstruct the likely intended meaning of a word. This process uses context to narrow the possible senses down to the probable ones. The context includes such things as the ideas conveyed by adjacent words and nearby phrases, the known or probable purpose and register of the conversation or document, and the orientation (time and place) implied or expressed. The disambiguation is thus context-sensitive. Advanced semantic analysis has resulted in a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology Of Nephron
Renal physiology (Latin language, 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 (medicine), 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, 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 cell (biology), cells and surrounded by capillary, capillaries. The major functions of these lining cells are the reabsorption of water and small m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerular Filtration Rate
Renal functions include maintaining an acid–base balance; regulating fluid balance; regulating sodium, potassium, and other electrolytes; clearing 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. One of the measures of kidney function is the glomerular filtration rate (GFR). Glomerular filtration rate describes the flow rate of filtered fluid through the kidney. Creatinine clearance rate (CCr or CrCl) is the volume of blood plasma that is cleared of creatinine per unit time and is a useful measure for approximating the GFR. Creatinine clearance exceeds GFR due to creatinine secretion, which can be blocked by cimetidine. Both GFR and CCr may be accurately calculated by comparative measurements of substances in the blood and urine, or estimated by formulas using just a blood test result (eGFR and eCCr) The results of these tests are used to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renal Function
Assessment of kidney function occurs in different ways, using the presence of symptoms and signs, as well as measurements using urine tests, blood tests, and medical imaging. Functions of a healthy kidney include maintaining a person's fluid balance, maintaining an acid-base balance; regulating electrolytes including sodium, potassium, and other electrolytes; clearing toxins; regulating blood pressure; and regulating hormones, such as erythropoietin; and activation of vitamin D. Introduction The functions of the kidney include 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 ... [...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 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerulus , a hemorrhage of the bladder
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''Glomerulus'' () is a common term used in anatomy to describe globular structures of entwined vessels, fibers, or neurons. ''Glomerulus'' is the diminutive of the Latin ''glomus'', meaning "ball of yarn". ''Glomerulus'' may refer to: * the filtering unit of the kidney; see Glomerulus (kidney). * a structure in the olfactory bulb; see Glomerulus (olfaction). * the contact between specific cells in the cerebellum; see Glomerulus (cerebellum). See also *Glomerulation Glomerulation refers to bladder hemorrhages which are thought to be associated with some types of interstitial cystitis (IC). The presence of glomerulations, also known as petechial hemorrhages, in the bladder suggests that the bladder wall has bee ... [...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 modi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secretion
440px Secretion is the movement of material from one point to another, such as a secreted chemical substance from a cell or gland. In contrast, excretion is the removal of certain substances or waste products from a cell or organism. The classical mechanism of cell secretion is via secretory portals at the plasma membrane called porosomes. Porosomes are permanent cup-shaped lipoprotein structures embedded in the cell membrane, where secretory vesicles transiently dock and fuse to release intra-vesicular contents from the cell. Secretion in bacterial species means the transport or translocation of effector molecules for example: proteins, enzymes or toxins (such as cholera toxin in pathogenic bacteria e.g. '' Vibrio cholerae'') from across the interior (cytoplasm or cytosol) of a bacterial cell to its exterior. Secretion is a very important mechanism in bacterial functioning and operation in their natural surrounding environment for adaptation and survival. In eukaryotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reabsorption
In renal physiology, reabsorption or tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid (pre-urine) and returns them to the circulating blood. It is called ''reabsorption'' (and not ''absorption'') because these substances have already been absorbed once (particularly in the intestines) and the body is reclaiming them from a post glomerular fluid stream that is on its way to becoming urine (that is, they will soon be lost to the urine unless they are reabsorbed from the tubule into the peritubular capillaries. This happens as a result of sodium transport from the lumen into the blood by the Na+/K+ATPase in the basolateral membrane of the epithelial cells. Thus, the glomerular filtrate becomes more concentrated, which is one of the steps in forming urine. Nephrons are divided into five segments, with different segments responsible for reabsorbing different substances. Reabsorption allows many useful solutes (primarily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillary
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 pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
