82-576: Rognon is culinary French for kidney and may refer to: Rognon (Marne) , a river in France, tributary of the Marne Rognon (Scey) , a river in France, tributary of the Scey (Rhône basin) Bourdons-sur-Rognon Lanques-sur-Rognon Rognon, Doubs Charles Amédée Rognon Rebecq-Rognon a rock rognon (synonym: nunatak ) projecting through
164-434: A glomerular filtration rate (GFR) of less than 15 or the need for renal replacement therapy . It is also equivalent to stage 5 chronic kidney disease . Treatment of acute failure depends on the underlying cause. Treatment of chronic failure may include hemodialysis , peritoneal dialysis , or a kidney transplant . Hemodialysis uses a machine to filter the blood outside the body. In peritoneal dialysis specific fluid
246-443: A glacier Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Rognon . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Rognon&oldid=1052199048 " Category : Disambiguation pages Hidden categories: Short description
328-499: A pathological diagnosis. A renal pathologist is a physician who has undergone general training in anatomic pathology and additional specially training in the interpretation of renal biopsy specimens. Ideally, multiple core sections are obtained and evaluated for adequacy (presence of glomeruli) intraoperatively. A pathologist/pathology assistant divides the specimen(s) for submission for light microscopy, immunofluorescence microscopy and electron microscopy. The pathologist will examine
410-491: A portion of medulla called a renal pyramid . Between the renal pyramids are projections of cortex called renal columns . The tip, or papilla , of each pyramid empties urine into a minor calyx ; minor calyces empty into major calyces , and major calyces empty into the renal pelvis . This becomes the ureter. At the hilum, the ureter and renal vein exit the kidney and the renal artery enters. Hilar fat and lymphatic tissue with lymph nodes surround these structures. The hilar fat
492-439: A renal failure index (RFI) greater than 3 are helpful in confirming acute renal failure. Those with end stage renal failure who undergo haemodialysis have higher risk of spontaneous intra-abdominal bleeding than the general population (21.2%) and non-occlusive mesenteric ischemia (18.1%). Meanwhile, those undergoing peritoneal dialysis have a higher chance of developing peritonitis and gastrointestinal perforation . However,
574-652: A tight hairpin configuration of the tubules, water and ion permeability in the descending limb of the loop, water impermeability in the ascending loop, and active ion transport out of most of the ascending limb. In addition, passive countercurrent exchange by the vessels carrying the blood supply to the nephron is essential for enabling this function. The kidney participates in whole-body homeostasis , regulating acid–base balance , electrolyte concentrations, extracellular fluid volume , and blood pressure . The kidney accomplishes these homeostatic functions both independently and in concert with other organs, particularly those of
656-476: A variety of causes, generally classified as prerenal , intrinsic , and postrenal . Many people diagnosed with paraquat intoxication experience AKI, sometimes requiring hemodialysis . The underlying cause must be identified and treated to arrest the progress, and dialysis may be necessary to bridge the time gap required for treating these fundamental causes. Chronic kidney disease (CKD) can also develop slowly and, initially, show few symptoms. CKD can be
738-456: Is homologous with the vas deferens of amniotes. However, the situation is not always so simple; in cartilaginous fish and some amphibians, there is also a shorter duct, similar to the amniote ureter, which drains the posterior (metanephric) parts of the kidney, and joins with the archinephric duct at the bladder or cloaca . Indeed, in many cartilaginous fish, the anterior portion of the kidney may degenerate or cease to function altogether in
820-722: 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 , hyperkalemia , and volume overload . Complications of chronic failure also include heart disease , high blood pressure , and anaemia . Causes of acute kidney failure include low blood pressure , blockage of
902-408: Is an adjective meaning “relating to the kidneys”, and its roots are French or late Latin. Whereas according to some opinions, "renal" should be replaced with "kidney" in scientific writings such as "kidney artery", other experts have advocated preserving the use of "renal" as appropriate including in "renal artery". In humans, the kidneys are located high in the abdominal cavity , one on each side of
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#1732765491054984-476: Is another well-known cause of chronic failure. The majority of people affected with polycystic kidney disease have a family history of the disease. Systemic lupus erythematosus (SLE) is also a known cause of chronic kidney failure. Other genetic illnesses cause kidney failure, as well. Overuse of common drugs such as ibuprofen , and acetaminophen (paracetamol) can also cause chronic kidney failure. Some infectious disease agents, such as hantavirus , can attack
1066-542: Is associated with poor outcomes including higher risk of kidney function decline, hospitalization, and death. A recent PCORI -funded study of patients with kidney failure receiving outpatient hemodialysis found similar effectiveness between nonpharmacological and pharmacological treatments for depression. In the United States, acute failure affects about 3 per 1,000 people a year. Chronic failure affects about 1 in 1,000 people with 3 per 10,000 people newly developing
1148-560: Is believed to be the release into the bloodstream of muscle breakdown products – notably myoglobin , potassium , and phosphorus – that are the products of rhabdomyolysis (the breakdown of skeletal muscle damaged by ischemic conditions). The specific action on the kidneys is not fully understood, but may be due in part to nephrotoxic metabolites of myoglobin. Chronic kidney failure has numerous causes. The most common causes of chronic failure are diabetes mellitus and long-term, uncontrolled hypertension . Polycystic kidney disease
1230-450: Is considered a severe illness and requires some form of renal replacement therapy ( dialysis ) or kidney transplant whenever feasible. A normal GFR varies according to many factors, including sex, age, body size and ethnic background. Renal professionals consider the glomerular filtration rate (GFR) to be the best overall index of kidney function. The National Kidney Foundation offers an easy to use on-line GFR calculator for anyone who
1312-562: Is contiguous with a fat-filled cavity called the renal sinus . The renal sinus collectively contains the renal pelvis and calyces and separates these structures from the renal medullary tissue. The kidneys possess no overtly moving structures. The kidneys receive blood from the renal arteries , left and right, which branch directly from the abdominal aorta . The kidneys receive approximately 20–25% of cardiac output in adult human. Each renal artery branches into segmental arteries, dividing further into interlobar arteries , which penetrate
1394-500: Is different from Wikidata All article disambiguation pages All disambiguation pages Kidney In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organs that are a multilobar, multipapillary form of mammalian kidneys , usually without signs of external lobulation. They are located on the left and right in the retroperitoneal space , and in adult humans are about 12 centimetres ( 4 + 1 ⁄ 2 inches) in length. They receive blood from
1476-663: Is differentiated by the trend in the serum creatinine ; other factors that may help differentiate acute kidney failure from chronic kidney failure include anemia and the kidney size on sonography as chronic kidney disease generally leads to anemia and small kidney size. Acute kidney injury (AKI), previously called acute renal failure (ARF), is a rapidly progressive loss of renal function , generally characterized by oliguria (decreased urine production, quantified as less than 400 mL per day in adults, less than 0.5 mL/kg/h in children or less than 1 mL/kg/h in infants); and fluid and electrolyte imbalance . AKI can result from
1558-402: Is divided into three or more distinct lobes. The lobes consists of several small, irregularly arranged, lobules, each centred on a branch of the ureter. Birds have small glomeruli, but about twice as many nephrons as similarly sized mammals. The human kidney is fairly typical of that of mammals . Distinctive features of the mammalian kidney, in comparison with that of other vertebrates, include
1640-497: Is frequently used to cure renal cell carcinoma . Renal physiology is the study of kidney function . Nephrology is the medical specialty which addresses diseases of kidney function : these include CKD, nephritic and nephrotic syndromes , acute kidney injury , and pyelonephritis . Urology addresses diseases of kidney (and urinary tract) anatomy : these include cancer , renal cysts , kidney stones and ureteral stones , and urinary tract obstruction . The word “ renal ”
1722-526: Is indicated when the glomerular filtration rate has fallen very low or if the renal dysfunction leads to severe symptoms. Dialysis is a treatment that substitutes for the function of normal kidneys. Dialysis may be instituted when approximately 85%–90% of kidney function is lost, as indicated by a glomerular filtration rate (GFR) of less than 15. Dialysis removes metabolic waste products as well as excess water and sodium (thereby contributing to regulating blood pressure); and maintains many chemical levels within
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#17327654910541804-434: Is interested in knowing their glomerular filtration rate. (A serum creatinine level, a simple blood test, is needed to use the calculator.) Before the advancement of modern medicine, renal failure was often referred to as uremic poisoning. Uremia was the term for the contamination of the blood with urea. It is the presence of an excessive amount of urea in blood. Starting around 1847, this included reduced urine output, which
1886-456: Is measured in five stages, which are calculated using the person's GFR, or glomerular filtration rate . Stage 1 CKD is mildly diminished renal function, with few overt symptoms. Stages 2 and 3 need increasing levels of supportive care from their medical providers to slow and treat their renal dysfunction. People with stage 4 and 5 kidney failure usually require preparation towards active treatment in order to survive. Stage 5 CKD
1968-431: Is placed into the abdominal cavity and then drained, with this process being repeated multiple times per day. Kidney transplantation involves surgically placing a kidney from someone else and then taking immunosuppressant medication to prevent rejection . Other recommended measures from chronic disease include staying active and specific dietary changes. Depression is also common among patients with kidney failure, and
2050-428: Is sensed in the corresponding dermatome . Thus, pain in the flank region may be referred from corresponding kidney. Nephrons , the urine-producing functional structures of the kidney, span the cortex and medulla. The initial filtering portion of a nephron is the renal corpuscle , which is located in the cortex. This is followed by a renal tubule that passes from the cortex deep into the medullary pyramids. Part of
2132-469: Is slightly lower. The right kidney sits just below the diaphragm and posterior to the liver . The left kidney sits below the diaphragm and posterior to the spleen . On top of each kidney is an adrenal gland . The upper parts of the kidneys are partially protected by the 11th and 12th ribs . Each kidney, with its adrenal gland is surrounded by two layers of fat: the perirenal fat present between renal fascia and renal capsule and pararenal fat superior to
2214-426: Is the crush syndrome , when large amounts of toxins are suddenly released in the blood circulation after a long compressed limb is suddenly relieved from the pressure obstructing the blood flow through its tissues, causing ischemia . The resulting overload can lead to the clogging and the destruction of the kidneys. It is a reperfusion injury that appears after the release of the crushing pressure. The mechanism
2296-419: Is the peritoneum , while the posterior (rear) surface is the transversalis fascia . The superior pole of the right kidney is adjacent to the liver. For the left kidney, it is next to the spleen . Both, therefore, move down upon inhalation. A Danish study measured the median renal length to be 11.2 cm ( 4 + 7 ⁄ 16 in) on the left side and 10.9 cm ( 4 + 5 ⁄ 16 in) on
2378-450: Is the production of urine . These include the nitrogenous wastes urea , from protein catabolism , and uric acid , from nucleic acid metabolism. The ability of mammals and some birds to concentrate wastes into a volume of urine much smaller than the volume of blood from which the wastes were extracted is dependent on an elaborate countercurrent multiplication mechanism. This requires several independent nephron characteristics to operate:
2460-485: Is the specialty under Surgery that deals with kidney structure abnormalities such as kidney cancer and cysts and problems with urinary tract . Nephrologists are internists , and urologists are surgeons , whereas both are often called "kidney doctors". There are overlapping areas that both nephrologists and urologists can provide care such as kidney stones and kidney related infections . There are many causes of kidney disease . Some causes are acquired over
2542-495: Is the transport of molecules from this ultrafiltrate and into the peritubular capillary network that surrounds the nephron tubules. It is accomplished via selective receptors on the luminal cell membrane. Water is 55% reabsorbed in the proximal tubule. Glucose at normal plasma levels is completely reabsorbed in the proximal tubule. The mechanism for this is the Na /glucose cotransporter. A plasma level of 350 mg/dL will fully saturate
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2624-409: The bone marrow . Calcitriol , the activated form of vitamin D , promotes intestinal absorption of calcium and the renal reabsorption of phosphate . Renin is an enzyme which regulates angiotensin and aldosterone levels. Although the kidney cannot directly sense blood, long-term regulation of blood pressure predominantly depends upon the kidney. This primarily occurs through maintenance of
2706-448: The endocrine system . Various endocrine hormones coordinate these endocrine functions; these include renin , angiotensin II , aldosterone , antidiuretic hormone , and atrial natriuretic peptide , among others. Filtration, which takes place at the renal corpuscle , is the process by which cells and large proteins are retained while materials of smaller molecular weights are filtered from
2788-458: The extracellular fluid compartment, the size of which depends on the plasma sodium concentration. Renin is the first in a series of important chemical messengers that make up the renin–angiotensin system . Changes in renin ultimately alter the output of this system, principally the hormones angiotensin II and aldosterone . Each hormone acts via multiple mechanisms, but both increase the kidney's absorption of sodium chloride , thereby expanding
2870-418: The posterior pituitary gland . An increase in osmolality causes the gland to secrete antidiuretic hormone (ADH), resulting in water reabsorption by the kidney and an increase in urine concentration. The two factors work together to return the plasma osmolality to its normal levels. Various calculations and methods are used to try to measure kidney function. Renal clearance is the volume of plasma from which
2952-451: The renal fascia . The human kidney is a bean-shaped structure with a convex and a concave border. A recessed area on the concave border is the renal hilum , where the renal artery enters the kidney and the renal vein and ureter leave. The kidney is surrounded by tough fibrous tissue, the renal capsule , which is itself surrounded by perirenal fat , renal fascia , and pararenal fat . The anterior (front) surface of these tissues
3034-406: The spine , and lie in a retroperitoneal position at a slightly oblique angle. The asymmetry within the abdominal cavity, caused by the position of the liver , typically results in the right kidney being slightly lower and smaller than the left, and being placed slightly more to the middle than the left kidney. The left kidney is approximately at the vertebral level T12 to L3 , and the right
3116-504: The urinary bladder harbour specialized parasites , monogeneans of the family Polystomatidae. The kidneys of reptiles consist of a number of lobules arranged in a broadly linear pattern. Each lobule contains a single branch of the ureter in its centre, into which the collecting ducts empty. Reptiles have relatively few nephrons compared with other amniotes of a similar size, possibly because of their lower metabolic rate . Birds have relatively large, elongated kidneys, each of which
3198-409: 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 is often based on a combination of factors such as decreased urine production or increased serum creatinine . Diagnosis of chronic failure is based on
3280-529: The adult. In the most primitive vertebrates, the hagfish and lampreys , the kidney is unusually simple: it consists of a row of nephrons, each emptying directly into the archinephric duct. Invertebrates may possess excretory organs that are sometimes referred to as "kidneys", but, even in Amphioxus , these are never homologous with the kidneys of vertebrates, and are more accurately referred to by other names, such as nephridia . In amphibians , kidneys and
3362-461: The assessment of renal disease. The role of the renal biopsy is to diagnose renal disease in which the etiology is not clear based upon noninvasive means (clinical history, past medical history, medication history, physical exam, laboratory studies, imaging studies). In general, a renal pathologist will perform a detailed morphological evaluation and integrate the morphologic findings with the clinical history and laboratory data, ultimately arriving at
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3444-495: The basis of a detailed medical history , and physical examination . The medical history takes into account present and past symptoms, especially those of kidney disease; recent infections; exposure to substances toxic to the kidney; and family history of kidney disease. Kidney function is tested by using blood tests and urine tests . The most common blood tests are creatinine , urea and electrolytes . Urine tests such as urinalysis can evaluate for pH, protein, glucose, and
3526-487: The blood and move it to the filtrate which helps to increase the pH of the blood. On the basal side of the cell there is a HCO 3 /Cl exchanger and a Cl/K co-transporter (facilitated diffusion). When the reaction is pushed to the left it also increases the HCO 3 concentration in the cell and HCO 3 is then able to move out into the blood which additionally raises the pH. The intercalated B cell responds very similarly, however,
3608-425: The blood moves through a small network of small veins ( venules ) that converge into interlobular veins . As with the arteriole distribution, the veins follow the same pattern: the interlobular provide blood to the arcuate veins then back to the interlobar veins , which come to form the renal veins which exit the kidney. The kidney and nervous system communicate via the renal plexus , whose fibers course along
3690-481: The blood supply to the kidneys is suddenly interrupted or when the kidneys become overloaded with toxins. Causes of acute kidney injury include accidents, injuries, or complications from surgeries in which the kidneys are deprived of normal blood flow for extended periods of time. Heart-bypass surgery is an example of one such procedure. Drug overdoses, accidental or from chemical overloads of drugs such as antibiotics or chemotherapy, along with bee stings may also cause
3772-407: The blood to make an ultrafiltrate that eventually becomes urine. The adult human kidney generates approximately 180 liters of filtrate a day, most of which is reabsorbed. The normal range for a twenty four hour urine volume collection is 800 to 2,000 milliliters per day. The process is also known as hydrostatic filtration due to the hydrostatic pressure exerted on the capillary walls. Reabsorption
3854-493: 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 about 12,500 nephrons. The kidneys also carry out functions independent of
3936-426: The body is experiencing acidic conditions. Under acidic conditions, the high concentration of CO 2 in the blood creates a gradient for CO 2 to move into the cell and push the reaction HCO 3 + H ↔ H 2 CO 3 ↔ CO 2 + H 2 O to the left. On the luminal side of the cell there is a H pump and a H/K exchanger. These pumps move H against their gradient and therefore require ATP. These cells will remove H from
4018-554: The body pH to a value of 7.4 by controlling the respiratory rate. When the body is experiencing acidic conditions, it will increase the respiratory rate which in turn drives off CO 2 and decreases the H concentration, therefore increasing the pH. In basic conditions, the respiratory rate will slow down so that the body holds onto more CO 2 and increases the H concentration and decreases the pH. The kidneys have two cells that help to maintain acid-base homeostasis: intercalated A and B cells. The intercalated A cells are stimulated when
4100-412: The body's acid–base balance are the kidneys and lungs. Acid–base homeostasis is the maintenance of pH around a value of 7.4. The lungs are the part of respiratory system which helps to maintain acid–base homeostasis by regulating carbon dioxide (CO 2 ) concentration in the blood. The respiratory system is the first line of defense when the body experiences and acid–base problem. It attempts to return
4182-437: The body. Life expectancy is 5–10 years for those on dialysis; some live up to 30 years. Dialysis can occur via the blood (through a catheter or arteriovenous fistula ), or through the peritoneum ( peritoneal dialysis ) Dialysis is typically administered three times a week for several hours at free-standing dialysis centers, allowing recipients to lead an otherwise essentially normal life. Many renal diseases are diagnosed on
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#17327654910544264-441: The condition each year. In Canada, the lifetime risk of kidney failure or end-stage renal disease (ESRD) was estimated to be 2.66% for men and 1.76% for women. Acute failure is often reversible while chronic failure often is not. With appropriate treatment many with chronic disease can continue working. Kidney failure can be divided into two categories: acute kidney failure or chronic kidney failure . The type of renal failure
4346-555: The course of life, such as diabetic nephropathy whereas others are congenital , such as polycystic kidney disease . Medical terms related to the kidneys commonly use terms such as renal and the prefix nephro- . The adjective renal , meaning related to the kidney, is from the Latin rēnēs , meaning kidneys; the prefix nephro- is from the Ancient Greek word for kidney, nephros (νεφρός) . For example, surgical removal of
4428-504: The extracellular fluid compartment and raising blood pressure. When renin levels are elevated, the concentrations of angiotensin II and aldosterone increase, leading to increased sodium chloride reabsorption, expansion of the extracellular fluid compartment, and an increase in blood pressure. Conversely, when renin levels are low, angiotensin II and aldosterone levels decrease, contracting the extracellular fluid compartment, and decreasing blood pressure. The two organ systems that help regulate
4510-468: The goal of treatment, as with AKI, is to return the person to baseline kidney function, typically measured by serum creatinine . Like AKI, AoCRF can be difficult to distinguish from chronic kidney disease if the person has not been monitored by a physician and no baseline (i.e., past) blood work is available for comparison. Symptoms can vary from person to person. Someone in early stage kidney disease may not feel sick or notice symptoms as they occur. When
4592-427: The kidney is a nephrectomy , while a reduction in kidney function is called renal dysfunction . Generally, humans can live normally with just one kidney, as one has more functioning renal tissue than is needed to survive. Only when the amount of functioning kidney tissue is greatly diminished does one develop chronic kidney disease . Renal replacement therapy , in the form of dialysis or kidney transplantation ,
4674-468: The kidney with podocin and nephrin expressed in glomeruli, Solute carrier family protein SLC22A8 expressed in proximal tubules, calbindin expressed in distal tubules and aquaporin 2 expressed in the collecting duct cells. The mammalian kidney develops from intermediate mesoderm . Kidney development , also called nephrogenesis , proceeds through a series of three successive developmental phases:
4756-426: The kidney, with only some 50 genes being highly specific for the kidney. Many of the corresponding kidney specific proteins are expressed in the cell membrane and function as transporter proteins. The highest expressed kidney specific protein is uromodulin , the most abundant protein in urine with functions that prevent calcification and growth of bacteria. Specific proteins are expressed in the different compartments of
4838-512: The kidneys fail to filter properly, waste accumulates in the blood and the body, a condition called azotemia . Very low levels of azotemia may produce few, if any, symptoms. If the disease progresses, symptoms become noticeable (if the failure is of sufficient degree to cause symptoms). Kidney failure accompanied by noticeable symptoms is termed uraemia . Symptoms of kidney failure include the following: Acute kidney injury (previously known as acute renal failure) – or AKI – usually occurs when
4920-687: The kidneys, causing kidney failure. The APOL1 gene has been proposed as a major genetic risk locus for a spectrum of nondiabetic renal failure in individuals of African origin, these include HIV-associated nephropathy (HIVAN), primary nonmonogenic forms of focal segmental glomerulosclerosis , and hypertension affiliated chronic kidney disease not attributed to other etiologies. Two western African variants in APOL1 have been shown to be associated with end stage kidney disease in African Americans and Hispanic Americans. Chronic kidney failure
5002-512: The long term consequence of irreversible acute disease or part of a disease progression. CKD is divided into 5 different stages (1–5) according to the estimated glomerular filtration rate (eGFR). In CKD1 eGFR is normal and in CKD5 eGFR has decreased to less than 15 ml/min. Acute kidney injuries can be present on top of chronic kidney disease, a condition called acute-on-chronic kidney failure (AoCRF). The acute part of AoCRF may be reversible, and
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#17327654910545084-487: The management of kidney disease include chemical and microscopic examination of the urine ( urinalysis ), measurement of kidney function by calculating the estimated glomerular filtration rate (eGFR) using the serum creatinine ; and kidney biopsy and CT scan to evaluate for abnormal anatomy. Dialysis and kidney transplantation are used to treat kidney failure ; one (or both sequentially) of these are almost always used when renal function drops below 15%. Nephrectomy
5166-444: The membrane proteins are flipped from the intercalated A cells: the proton pumps are on the basal side and the HCO 3 /Cl exchanger and K/Cl co-transporter are on the luminal side. They function the same, but now release protons into the blood to decrease the pH. The kidneys help maintain the water and salt level of the body. Any significant rise in plasma osmolality is detected by the hypothalamus , which communicates directly with
5248-520: The multilobed reniculate kidneys of pinnipeds and cetaceans . Kidneys of various animals show evidence of evolutionary adaptation and have long been studied in ecophysiology and comparative physiology . Kidney morphology, often indexed as the relative medullary thickness, is associated with habitat aridity among species of mammals and diet (e.g., carnivores have only long loops of Henle). Kidney failure Kidney failure , also known as renal failure or end-stage renal disease ( ESRD ),
5330-438: The nephrons. For example, they convert a precursor of vitamin D to its active form, calcitriol ; and synthesize the hormones erythropoietin and renin . Chronic kidney disease (CKD) has been recognized as a leading public health problem worldwide. The global estimated prevalence of CKD is 13.4%, and patients with kidney failure needing renal replacement therapy are estimated between 5 and 7 million. Procedures used in
5412-407: The onset of acute kidney injury. Unlike chronic kidney disease, however, the kidneys can often recover from acute kidney injury, allowing the person with AKI to resume a normal life. People with acute kidney injury require supportive treatment until their kidneys recover function, and they often remain at increased risk of developing future kidney failure. Among the accidental causes of renal failure
5494-402: 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
5576-453: The patient's renal disease. In the majority of vertebrates, the mesonephros persists into the adult, albeit usually fused with the more advanced metanephros ; only in amniotes is the mesonephros restricted to the embryo. The kidneys of fish and amphibians are typically narrow, elongated organs, occupying a significant portion of the trunk. The collecting ducts from each cluster of nephrons usually drain into an archinephric duct , which
5658-533: The presence of blood. Microscopic analysis can also identify the presence of urinary casts and crystals. The glomerular filtration rate (GFR) can be directly measured ("measured GFR", or mGFR) but this rarely done in everyday practice. Instead, special equations are used to calculate GFR ("estimated GFR", or eGFR). Renal ultrasonography is essential in the diagnosis and management of kidney-related diseases. Other modalities, such as CT and MRI , should always be considered as supplementary imaging modalities in
5740-467: The presence of the renal pelvis and renal pyramids and a clearly distinguishable cortex and medulla. The latter feature is due to the presence of elongated loops of Henle ; these are much shorter in birds, and not truly present in other vertebrates (although the nephron often has a short intermediate segment between the convoluted tubules). It is only in mammals that the kidney takes on its classical "kidney" shape, although there are some exceptions, such as
5822-399: The pronephros, mesonephros, and metanephros. The metanephros are primordia of the permanent kidney. The kidneys excrete a variety of waste products produced by metabolism into the urine. The microscopic structural and functional unit of the kidney is the nephron . It processes the blood supplied to it via filtration, reabsorption, secretion and excretion; the consequence of those processes
5904-712: The rate of acute pancreatitis does not differ from the general population. The treatment of acute kidney injury depends on the cause. The treatment of chronic kidney failure may include renal replacement therapy: hemodialysis , peritoneal dialysis , or kidney transplant . In non-diabetics and people with type 1 diabetes , a low protein diet is found to have a preventive effect on progression of chronic kidney disease. However, this effect does not apply to people with type 2 diabetes . A whole food, plant-based diet may help some people with kidney disease. A high protein diet from either animal or plant sources appears to have negative effects on kidney function at least in
5986-464: The renal arteries to reach each kidney. Input from the sympathetic nervous system triggers vasoconstriction in the kidney, thereby reducing renal blood flow . The kidney also receives input from the parasympathetic nervous system , by way of the renal branches of the vagus nerve ; the function of this is yet unclear. Sensory input from the kidney travels to the T10–11 levels of the spinal cord and
6068-440: The renal capsule and extend through the renal columns between the renal pyramids. The interlobar arteries then supply blood to the arcuate arteries that run through the boundary of the cortex and the medulla. Each arcuate artery supplies several interlobular arteries that feed into the afferent arterioles that supply the glomeruli. Blood drains from the kidneys, ultimately into the inferior vena cava . After filtration occurs,
6150-493: The renal cortex, a medullary ray is a collection of renal tubules that drain into a single collecting duct . Renal histology is the study of the microscopic structure of the kidney. The adult human kidney contains at least 26 distinct cell types . Distinct cell types include: In humans, about 20,000 protein coding genes are expressed in human cells and almost 70% of these genes are expressed in normal, adult kidneys. Just over 300 genes are more specifically expressed in
6232-412: The reverse of reabsorption: molecules are transported from the peritubular capillary through the interstitial fluid, then through the renal tubular cell and into the ultrafiltrate. The last step in the processing of the ultrafiltrate is excretion : the ultrafiltrate passes out of the nephron and travels through a tube called the collecting duct , which is part of the collecting duct system , and then to
6314-476: The right side in adults. Median renal volumes were 146 cm ( 8 + 15 ⁄ 16 cu in) on the left and 134 cm ( 8 + 3 ⁄ 16 cu in) on the right. The functional substance, or parenchyma , of the human kidney is divided into two major structures: the outer renal cortex and the inner renal medulla . Grossly, these structures take the shape of eight to 18 cone-shaped renal lobes , each containing renal cortex surrounding
6396-471: The specimen using light microscopy with multiple staining techniques (hematoxylin and eosin/H&E, PAS, trichrome, silver stain) on multiple level sections. Multiple immunofluorescence stains are performed to evaluate for antibody, protein and complement deposition. Finally, ultra-structural examination is performed with electron microscopy and may reveal the presence of electron-dense deposits or other characteristic abnormalities that may suggest an etiology for
6478-598: The substance is completely cleared from the blood per unit time. The filtration fraction is the amount of plasma that is actually filtered through the kidney. This can be defined using the equation. The kidney is a very complex organ and mathematical modelling has been used to better understand kidney function at several scales, including fluid uptake and secretion. Nephrology is the subspeciality under Internal Medicine that deals with kidney function and disease states related to renal malfunction and their management including dialysis and kidney transplantation . Urology
6560-399: The transporters and glucose will be lost in the urine. A plasma glucose level of approximately 160 is sufficient to allow glucosuria, which is an important clinical clue to diabetes mellitus. Amino acids are reabsorbed by sodium dependent transporters in the proximal tubule. Hartnup disease is a deficiency of the tryptophan amino acid transporter, which results in pellagra . Secretion is
6642-427: The ureters where it is renamed urine . In addition to transporting the ultrafiltrate, the collecting duct also takes part in reabsorption. The kidneys secrete a variety of hormones , including erythropoietin , calcitriol , and renin . Erythropoietin is released in response to hypoxia (low levels of oxygen at tissue level) in the renal circulation. It stimulates erythropoiesis (production of red blood cells) in
6724-436: Was thought to be caused by the urine mixing with the blood instead of being voided through the urethra. The term uremia is now used for the illness accompanying kidney failure. Two other urinary indices, are the fractional sodium excretion (FENa) index and the renal failure index (RFI). The renal failure index is equal to urine sodium times plasma creatinine divided by urine creatinine . A FENa score greater than 3% or
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