kidney

American Heritage Dictionary:

kid·ney

(kĭd'nē)

n., pl., -neys.

Anatomy. Either one of a pair of organs in the dorsal region of the vertebrate abdominal cavity, functioning to maintain proper water and electrolyte balance, regulate acid-base concentration, and filter the blood of metabolic wastes, which are then excreted as urine.
The kidney of certain animals, eaten as food.
An excretory organ of certain invertebrates.
Temperment; kind: a person of the same kidney.

[Middle English kidenei.]

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kidney

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has the plural form kidneys.

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Visual Food Lover's Guide:

Kidneys

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calf kidneys

The kidneys of butchered animals. Calf, lamb and heifer kidneys are tender and tasty. Pig, sheep and beef kidneys have a sharp and strong taste and a firmer texture. Beef and lamb kidneys are dark brown, pig's kidneys are pale red-brown, and calf kidneys are brown and paler than beef kidneys.

Buying 
Choose: plump, firm and shiny kidneys that have the characteristic color for the particular animal, without any ammonia smell.

Preparing 
Remove the skin covering the kidneys, cut them in two and remove the fat and internal tubes. To remove any unpleasant odor, boil them briefly, then drain before cooking, or soak for 1-2 hr in the fridge in salted water (1 tablespoon/15 ml of salt per 4 cups/1 l of water), rinse in cold water then, dry them.

Serving Ideas 
Kidneys are served in stews and pies. They work well with tomatoes, mushrooms, mustard, lemon juice, cream, red wine, Madeira and sherry.

Storing 
In the fridge: 1 day. 
In the freezer: use kidneys as soon as they are defrosted.

Cooking 
Broiled, sautéed or roasted: for the most tender kidneys.  
Braised: for less tender kidneys. Cook just until they are no longer red in the middle.

Nutritional Information

	braised lamb kidneys	simmered beef kidneys	braised pig kidneys	braised calf kidneys
protein	24 g	26 g	25 g	26 g
fat	4 g	3 g	5 g	6 g
cholesterol	565 mg	387 mg	480 mg	791 mg
calories	137	144	151	163
per 3.5 oz/100 g

Excellent source: protein, vitamin A (beef), vitamin B12, riboflavin, niacin and folic acid (lamb and beef), iron, phosphorus and zinc.  Kidneys are lean, but they contain a great deal of cholesterol.

Britannica Concise Encyclopedia:

kidney

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(click to enlarge)
Cross section of a kidney. The kidney is made up of an outermost cortex, a middle medulla, and an (credit: © Merriam-Webster Inc.)

One of a pair of organs that maintain water balance and expel metabolic wastes. Human kidneys are bean-shaped organs about 4 in. (10 cm) long, in the small of the back. They filter the entire 5-quart (about 4.5-liter) water content of the blood every 45 minutes. Glucose, minerals, and needed water are returned to the blood by reabsorption. The remaining fluid and wastes pass into collecting ducts, flowing to the ureter and bladder as urine. Each kidney has over 1 million functional units (nephrons) involved in the process of filtration and reabsorption. The kidneys also secrete renin, an enzyme involved in blood pressure regulation. Disorders include kidney failure, kidney stones, and nephritis. See also urinary system.

For more information on kidney, visit Britannica.com.

McGraw-Hill Science & Technology Encyclopedia:

Kidney

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An organ involved with the elimination of water and waste products from the body. In vertebrates the kidneys are paired organs located close to the spine dorsally in the body cavity. They consist of a number of smaller functional units called urinary tubules or nephrons. The nephrons open to large ducts, the collecting ducts, which open into a ureter. The two ureters run backward to open into the cloaca or into a urinary bladder. In mammals, the kidneys are bean-shaped and found between the thorax and the pelvis. The number, structure, and function of the nephrons vary with evolution and, in certain significant ways, with the adaptation of the animals to their various habitats.

In its most primitive form, found only in invertebrates, the nephron has a funnel opening into the coelomic cavity followed by a urinary tubule leading to an excretory pore. In amphibians, some of the tubules have this funnel, but most of the tubules have a Bowman capsule (see illustration). In all higher vertebrates, the nephron has the Bowman capsule, which surrounds a tuft of capillary loops, called the glomerulus, constituting the closed end of the nephron. The inner epithelial wall of the Bowman capsule is in intimate contact with the endothelial wall of the capillaries. The wall of the capillaries, together with the inner wall of the Bowman capsule, forms a membrane ideally suited for filtration of the blood.

Nephron from frog kidney, dissected to show glomerulus within Bowman capsule.

The blood pressure in the capillaries of the glomerulus causes filtering of blood by forcing fluid, small molecules, and ions through the membrane into the lumen of Bowman's capsule. This filtrate contains some of the proteins and all of the smaller molecules in the blood. As the filtrate passes down through the tubule, the walls of the tubule extract those substances not destined for excretion and return them to the blood in adjacent capillaries. Many substances which are toxic to the organism are moved in the opposite direction from the blood into the tubules. The urine thus produced by each nephron is conveyed by the collecting duct and ureter to the cloaca or bladder from which it can be eliminated.

In all classes of vertebrates the renal arteries deliver blood to the glomeruli and through a second capillary net to the tubules. The major blood supply to the kidney tubules comes, however, from the renal portal vein, which is found in all vertebrates except mammals and cyclostomes. Waste products from the venous blood can thus be secreted directly into the urinary tubules. See also Urinary system.

Oxford Food & Nutrition Dictionary:

kidney

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Usually from lamb, ox, or pig; a 150-g portion is a rich source of protein, niacin, iron, zinc, copper, selenium, vitamins A, B₁, B₂, B₁₂, and folate; a good source of vitamin B₆ and, unusually for a meat product, vitamin C; a source of iodine; contains about 9 g of fat, of which one-third is saturated; supplies 150 kcal (630 kJ).

Barron's Food Lover's Companion:

kidney

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One of the variety meats, the kidney is a glandular organ. The most popular kidneys for cooking are beef, veal, lamb and pork. They're easily distinguishable because beef and veal kidneys are multi-lobed while lamb and pork are single-lobed. In general, the texture is more tender and the flavor more delicate in younger animals. The kidneys from younger animals are pale while those from older animals become deep reddish-brown; they're also tougher and stronger-flavored. Look for kidneys that are firm, with a rich, even color. Avoid those with dry spots or a dull surface. Kidneys should be used the day they're purchased, or store loosely wrapped in the refrigerator for up to 1 day. Before cooking, remove skin and any excess fat. Soaking helps reduce the strong odor in kidneys from more mature animals. See a general cookbook for details pertaining to the particular type of kidney you wish to cook. Kidneys may be braised, broiled, simmered or cooked in casseroles, stews and dishes like the famous steak and kidney pie. All kidneys are a good source of protein, iron, phosphorus, vitamin A, thiamine and riboflavin.

Oxford Companion to the Body:

kidneys

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The kidneys are situated on each side of the vertebral column, at the level of the last (twelfth) rib. Each kidney is about 12 cm long and weighs about 150 g — about the size of a fist. Despite their small size, the two kidneys receive an enormous blood flow — about 1.2 litres/min in an adult — which is a quarter of the total output of the heart (5 litres/min).

One of the main functions of the kidneys is the removal from the body (excretion) of waste products such as urea, uric acid, and creatinine. However, the kidneys' role is not merely excretion. They are also regulatory organs, controlling the volume and the composition of the body fluids and maintaining the correct osmolality, ion concentrations, and acid-base status of the body.

Each kidney is bean-shaped, with a slit opening — termed the hilus — through which pass the renal artery and vein, the renal nerves and lymphatics, and the ureter, which connects the kidney to the bladder (Fig. 1). A tough connective tissue capsule covers the outer layer of the kidney, the cortex. The deeper part of the kidney, the medulla, consists of a number (6-18) of conical pyramids, the tips of which (papillae) project into the funnel-shaped urine collectors — the renal calyxes (calices) — which merge to form the funnel-shaped upper end of the ureter — the renal pelvis. (Renal, pertaining to the kidney, from its Latin name, ren.)

The nephron is the functional unit of the kidney. (Nephros is the Greek for kidney.) Each kidney has about one million nephrons, and the total length of the nephrons in the body is about 100 miles!

The nephron begins as a Bowman's capsule — the blind end of the nephron — invaginated by a knot of capillaries, the glomerulus (glomerular capillaries). A Bowman's capsule and its glomerular capillaries are together termed a renal corpuscle. Sir William Bowman, British surgeon and histologist, described this in 1842.

The rest of the nephron consists of the proximal convoluted tubule, proximal straight tubule, loop of Henle, and distal convoluted tubule. The distal tubules join to form collecting tubules which in turn join to form collecting ducts, which open at the tip of the renal papilla (Fig. 2).

The Bowman's capsules, proximal tubules, and distal tubules are situated in the renal cortex, whereas the loops of Henle and the collecting ducts extend down through the medulla.

Fig. 1 Diagrammatic cross section of the kidney
(Click to enlarge)

The function of the kidneys is to produce urine, a fluid of variable volume and composition (within limits), depending on the need of the body to excrete or conserve water or solutes. The first step in the production of urine is the filtration of plasma passing through the kidney. This filtration (sometimes called ultrafiltration as it occurs at the molecular level rather than gross particle level) occurs from the glomerular capillaries into the Bowman's capsule to form tubular fluid. The glomerular filter prevents plasma proteins from passing into the nephrons, but is permeable to all other plasma constituents (such as ions, glucose, amino acids, urea, etc). Thus filtration in the kidney is essentially non-selective — substances which the body needs to retain are filtered, as well as those substances which need to be excreted.

Filtration is the bulk flow of water through a semipermeable membrane (filter), carrying with it those solutes which can pass through the filter. As mentioned above, the glomerular filter only excludes plasma proteins. Water moves by bulk flow through the filter as a consequence of pressure gradients. Immediately upstream and downstream from the glomerular capillaries, there are blood vessels which have smooth muscle in their walls, so that they can constrict or dilate, and so alter the resistance to the flow of blood. These vessels are, respectively, the afferent and efferent arterioles. They permit precise regulation of the hydrostatic pressure of the blood in the glomerular capillaries, which is maintained at a higher level than in capillaries in other parts of the body. This force drives plasma from the glomerular capillaries into the nephrons. However, two forces work in opposition to this movement. One is the osmotic pressure exerted by the plasma proteins, which increases as filtration proceeds and the proteins, because they are not filtered, get more concentrated. The other force opposing filtration is the hydrostatic pressure within the Bowman's capsule. The resultant is a net filtration pressure which diminishes as blood flows through the glomerlus. The amount of filtration that actually occurs is known as the glomerular filtration rate, or GFR. It is about 120 ml/min (180 l/day). This seems an enormous volume — and it is an enormous volume — but it is important to realize that it is only a small fraction of the total plasma delivered to the kidneys in the blood. In this respect, the kidneys are rather different from our everyday experiences of filters. For example, when we make filter coffee, we pour water over coffee in the filter, and essentially all the water goes through the filter, leaving a ‘sludge’ of coffee grounds in the filter. If all of the plasma delivered to the kidneys passed through the glomerular filters into the nephrons, the filters would be clogged with a ‘sludge’ of red cells, white cells, and plasma proteins. This is prevented because only 20% of the plasma arriving at the filter actually passes through. The remaining 80% continues into the efferent arterioles.

The volume of plasma in the whole of the circulating blood is only about 3 litres, yet we filter 180 litres per day of it. This apparently paradoxical situation is possible because, after filtration, almost all (99%) of the plasma is reabsorbed along the nephron, so can be filtered again and again (60 times a day!). The selectivity of the kidney — how it is able to conserve some substances and excrete others — is due to the transport processes (reabsorption and secretion) which occur along the nephron, modifying the composition of the glomerular filtrate.

In the nephrons, the terms ‘reabsorption’ and ‘secretion’ indicate the direction of movement. Reabsorption is movement of a substance from the tubular fluid, through the tubular cells or between them and thence into the blood. Secretion is movement in the opposite direction.

If a transport process is directly linked to the consumption of metabolic energy, it is termed ‘active’. In the kidney, the quantitatively most important active transport process is the reabsorption of sodium ions (Na⁺). Up to 80% of the kidneys' oxygen consumption drives this process, and because the energy comes from the breakdown of adenosine triphosphate (ATP), Na⁺ active transporters are termed ATPases. There are many other transporter molecules in the nephron cells, many driven by gradients (e.g. for Na⁺) set up by active transport. Such transport is termed ‘secondary active’ for example, glucose reabsorption is via a transporter which also carries Na⁺ into the cell, with the driving force being the Na⁺ concentration gradient set up by the active transport of Na⁺ out of the cell. In addition to ATPases and transporter molecules, nephron cell membranes also contain proteins which constitute ‘channels’ for the passage of ions, neutral molecules or water.

The proximal tubule reabsorbs about 70% of the filtered Na⁺, 70% of the filtered water, and, normally, 100% of the filtered glucose and amino acids. Diabetes mellitus, the condition in which glucose is excreted in the urine, is caused by the failure to maintain the normal plasma level of glucose. In diabetes mellitus the plasma glucose concentration is increased, so the filtered load of glucose is increased; if the increase is big enough the nephrons are unable to reabsorb it all, and some appears in the urine.

The sodium which is reabsorbed in the ascending loop of Henle is not accompanied by water, since this part of the nephron is impermeable to water. Consequently, Na⁺ transport at this site lowers the solute concentration of the tubular fluid, and raises that of the fluid in the interstitial space of the medulla, which surrounds the tubules. This high medullary concentration is the osmotic driving force for water reabsorption in the collecting tubules under the influence of ADH (see below).

Just how efficient the kidneys are at controlling our body fluid volume is demonstrated by the constancy of the body weight from day to day. Even if you spend the evening in the pub and drink a couple of kilograms of beer, your body weight will be back to normal the next day!

The volume of urine excreted by the kidneys can vary between 400 ml/day, and about 25 L/day. The main determinants of urine volume are the osmotic concentration of the body fluids, and the effective circulating volume (the volume of blood circulating around the body in the vascular system). These regulate the urine volume primarily by affecting the release or production of hormones which control renal function.

If our fluid intake is less than the fluid loss, the body fluid osmotic concentration (osmolality) increases — the solutes of the body are in a smaller volume than normal, so their concentration is higher. This increased osmotic concentration is detected by ‘osmoreceptors’ in the brain, and these lead to the release, from the posterior pituitary gland, of the peptide antidiuretic hormone (ADH), also called vasopressin. This hormone circulates in the blood and binds to ‘V2’ receptors on the cells of the kidneys' collecting tubules. It causes them in effect to become more permeable to water, by incorporating water channels in their cell membranes. Because there is always an osmotic gradient tending to move water out of these tubules into the fluid around them and thence into the blood, more water is reabsorbed, the volume of urine is decreased and it becomes more concentrated. The raised osmolality of the body fluids is thus corrected. Because of this continual homeostatic mechanism, the urine volume, which can range from 400 ml/day to 25 litres/day is primarily determined by the level of circulating ADH. A typical volume is 1.5 litres/day.

Decreases in the effective circulating volume also increase ADH release, but in addition such decreases increase the release of renin from the juxtaglomerular apparatus of the kidney (a region of each nephron where the afferent arteriole and distal tubule are in contact). Renin is an enzyme, which acts on a plasma protein (a₂ globulin) to release a 10-amino acid peptide, angiotensin I. This in turn is converted, by an enzyme present in blood vessel walls, (ACE — angiotensin converting enzyme), to an 8 amino acid peptide, angiotensin II.

Angiotensin II increases nephron Na⁺ reabsorption. Since water follows Na⁺, water reabsorption also increases, and urine volume falls. Angiotensin II acts directly on the nephrons, and also causes ADH release and the release of another Na⁺-retaining hormone, aldosterone.

Another important regulatory function of the kidney is the control of acid-base homeostasis. In general, the metabolism of the body produces excess H⁺, and this is secreted into the urine by the nephron cells. The pH of the blood and extracellular fluid is kept constant at 7.4, but to achieve this, the kidneys can vary the urine pH from 4.5-8.0.

Kidney function may become impaired, leading to renal failure. There are many potential causes of renal failure, including reduction of the renal blood supply (e.g. as a result of major haemorrhage), toxins and disease organisms, and blockages of the urinary tract. If the kidneys fail, one of the first signs is the accumulation of urea and other nitrogenous waste in the blood —uraemia. This may require treatment by dialysis or by organ transplantation. However, other problems associated with failing kidneys relate to the fact that the kidneys are themselves important endocrine glands. They produce the hormone erythropoietin, which stimulates bone marrow to produce red blood cells, and also convert the precursor form of vitamin D to the active form. Both of these functions can be disrupted in renal failure, leading to anaemia and to disturbance of calcium supply to the bones.

If just one kidney fails, or is surgically removed, then changes take place in the remaining one to enable it to maintain homeostasis. Although the number of nephrons in the surviving kidney does not increase, the glomerular filtration rate of each individual nephron increases, so that the overall glomerular filtration rate increases to approach that which was previously achieved with two kidneys.

— Chris Lote

Bibliography

Lote, C. J. (2000). Principles of renal physiology, (4th edn). Kluwer, Amsterdam

Oxford Dictionary of Sports Science & Medicine:

kidneys

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The major excretory and osmoregulatory organs in the body. A pair of kidneys lie dorsally (at the back), in the abdomen. The kidneys also act as endocrine organs releasing erythropoietin, a hormone that regulates red blood cell production.

Answer of the Day:

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Kidneys (bottom)

How large are your kidneys: a. the size of the size of your fists, b. the size of two ping-pong balls, or c. the size of two quarters?

If you chose a, you're right. You have two kidneys, each one the size of a fist, located just above the small of your back. Though, it's not always easy to diagnose, just about one in every ten adults in the US has suffered some damage to his kidneys. Chronic kidney disease, or a slow deterioration of renal function, are most often caused by diabetes and high blood pressure. Since the same things that cause diabetes and high blood pressure usually also cause obesity, you can use the same tricks to prevent the diseases that you would use to keep weight off: eat properly, and get as much exercise and sleep into your routine as you can. Today is World Kidney Day, observed annually on the second Thursday in March, to raise awareness of kidney disease and how we can prevent it.

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Dictionary of Cultural Literacy: Health:

kidneys

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A pair of organs, the principal parts of the excretory system, located above the waistline at the back of the abdominal cavity. The kidneys filter waste materials from the blood, excreting these wastes in the form of urine; they also regulate the amounts of water and other chemicals in body fluids.

Word Tutor:

kidney

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IN BRIEF: An organ that filters the blood.

The sister donated her kidney to her twin.

LearnThatWord.com is a free vocabulary and spelling program where you only pay for results!

Sign Language Videos:

kidney

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sign description: The hand touches the portion of the back where the kidney is located.

Oxford Dictionary of Biochemistry:

kidney

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either of a pair of organs of vertebrates concerned with osmoregulation and the elimination of nitrogenous waste products. Kidneys of different species vary in structure according to the animal's mode of life, but their basic design and function is the same. Each kidney is enclosed in a capsule and is made up of an outer cortex and an inner medulla, and contains numerous nephrons and their associated blood supply. The nephrons filter constituents from the blood to form urine, which is discharged from the kidney via the ureter.

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Saunders Veterinary Dictionary:

kidney

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Either of the two organs in the lumbar region that filter the blood, excreting the end-products of body metabolism in the form of urine, and regulating the concentrations of hydrogen, sodium, potassium, phosphate and other ions in the extracellular fluid. Bean-shaped in the dog, cat, sheep and laboratory animals, lobed in the ox and some fetal animals such as the horse; irregularly lobed in birds. See also renal.

Dog kidney. By permission from Sack W, Wensing CJG, Dyce KM, Textbook of Veterinary Anatomy, Saunders, 2002

artificial k. — an extracorporeal device used as a substitute for nonfunctioning kidneys to remove endogenous metabolites from the blood, or as an emergency measure to remove exogenous poisons such as barbiturates. Called also hemodialyzer.
balloon k. — meat hygiene term for cystic kidney.
basal lamina k. — part of the filtration barrier of the kidney; is much thicker than most basal laminae.
cake k. — a solid, irregularly lobed organ of bizarre shape, formed by fusion of the two renal anlagen. Called also lump kidney.
cicatricial k. — a shriveled, irregular and scarred kidney due to suppurative pyelonephritis.
contracted k. — an atrophic kidney that may be scarred and granular.
duplicate k. — occurs in most species, without apparent increase in total renal mass.
enlarged k. — may be due to polycystic kidney disease, hydronephrosis, pyelonephritis or congenital absence of one kidney resulting in hypertrophy of the other.
fatty k. — one affected with fatty degeneration.
floating k. — one that is freely movable, especially a human kidney (normally more firmly fixed than those in quadrupeds); called also hypermobile kidney. See also nephroptosis.
Bovine kidney. By permission from Sack W, Wensing CJG, Dyce KM, Textbook of Veterinary Anatomy, Saunders, 2002
fused k. — a single anomalous organ developed as a result of fusion of the renal anlagen.
giant k. worm — dioctophyme renale.
Goldblatt k. — one with obstruction of its blood flow, resulting in renal hypertension. Produced experimentally in dogs.
horseshoe k. — an anomalous organ resulting from fusion of the corresponding poles of the renal anlagen.
hypermobile k. — one that is freely movable; called also floating kidney. See also nephroptosis.
lump k. — cake kidney.
k. meridian points — acupuncture points on the kidney meridian.
pelvic k. — a kidney which has failed to ascend from its primordial site to the roof of the abdomen.
polycystic k. disease — the most common congenital renal defect but most cases are sporadic and do not cause clinical illness because there is still sufficient renal mass to avoid uremia. In some cases the enlarged kidney is detected incidentally during a clinical examination. Rarely both kidneys are badly involved and the animal is dead at birth or dies soon afterwards. In some cases, there are signs of progressive renal failure, perhaps not until later in life. The defect is inherited in Persian cats, Cairn terriers and pigs. In Cairn terriers, cysts may also occur in the liver. See also feline perirenal cysts.
pulpy k. disease — see Clostridium perfringens enterotoxemia.
k. scan — radioimaging of a kidney by the use of a rectilinear scanner after the intravenous administration of a radiopaque material.
k. stones — see urolithiasis.
supernumerary k. — additional kidneys which develop as a consequence of two ureteric buds arising from one mesonephric duct so that two kidneys develop on the one side.
k. transplant — commonly and successfully performed in experimental dogs. Increasingly used as a therapeutic procedure in clinical veterinary medicine for renal failure in cats and dogs.
turkey egg k. — a speckled pattern caused by hemorrhagic glomeruli in diseases such as porcine erysipelas.
wandering k. — floating or hypermobile kidney. See also nephroptosis.
waxy k. — amyloid kidney.
white-spotted k. — focal nonsuppurative interstitial nephritis, seen most commonly in calves.

Mosby's Dental Dictionary:

kidney

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One of a pair of bean-shaped urinary organs in the dorsal part of the abdomen, one on each side of the vertebral column. The kidneys produce and eliminate urine through a complex filtration network and reabsorption system comprising more than 2 million nephrons. More than 2500 pints of blood pass through the kidneys every day.

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Random House Word Menu by Stephen Glazier

For a list of words related to kidney, see:

Endocrine System and Glands - kidney: either of a pair of bean-shaped glands in upper abdominal cavity that control amount of water in blood, maintain homeostasis, and excrete waste water as urine
Meats and Cuts of Meat
bean

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See words rhyming with "kidney."

Bradford's Crossword Solver's Dictionary:

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See crossword solutions for the clue Kidney.

Wikipedia on Answers.com:

Kidney

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For other uses, see Kidney (disambiguation).

Kidney

Human kidneys viewed from behind with spine removed
Latin	ren
Artery	renal artery
Vein	renal vein
Nerve	renal plexus

Right kidney

Left kidney

The kidneys are organs that serve several essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and regulation of blood pressure (via maintaining salt and water balance). They serve the body as a natural filter of the blood, and remove wastes which are diverted to the urinary bladder. In producing urine, the kidneys excrete wastes such as urea and ammonium, and they are also responsible for the reabsorption of water, glucose, and amino acids. The kidneys also produce hormones including calcitriol, erythropoietin, and the enzyme renin.

Located at the rear of the abdominal cavity in the retroperitoneum, the kidneys receive blood from the paired renal arteries, and drain into the paired renal veins. Each kidney excretes urine into a ureter, itself a paired structure that empties into the urinary bladder.

Renal physiology is the study of kidney function, while nephrology is the medical specialty concerned with kidney diseases. Diseases of the kidney are diverse, but individuals with kidney disease frequently display characteristic clinical features. Common clinical conditions involving the kidney include the nephritic and nephrotic syndromes, renal cysts, acute kidney injury, chronic kidney disease, urinary tract infection, nephrolithiasis, and urinary tract obstruction.^[1] Various cancers of the kidney exist; the most common adult renal cancer is renal cell carcinoma. Cancers, cysts, and some other renal conditions can be managed with removal of the kidney, or nephrectomy. When renal function, measured by glomerular filtration rate, is persistently poor, dialysis and kidney transplantation may be treatment options. Although they are not severely harmful, kidney stones can be a pain and a nuisance. The removal of kidney stones includes sound wave treatment to break up the stones into smaller pieces, which are then passed through the urinary tract. One common symptom of kidney stones is a sharp pain in the medial/lateral segments of the lower back.

Anatomy

Location

Surface projections of the organs of the trunk, showing kidneys at the level of T12 to L3.

In humans the kidneys are located in the abdominal cavity, more specifically in the paravertebral gutter and lie in a retroperitoneal position at a slightly oblique angle. There are two, one on each side of the spine. The asymmetry within the abdominal cavity caused by the liver typically results in the right kidney being slightly lower than the left, and left kidney being located slightly more medial than the right.^[2]^[3] The left kidney is approximately at the vertebral level T12 to L3,^[4] and the right slightly lower. The right kidney sits just below the diaphragm and posterior to the liver, the left below the diaphragm and posterior to the spleen. Resting on top of each kidney is an adrenal gland. The upper (cranial) parts of the kidneys are partially protected by the eleventh and twelfth ribs, and each whole kidney and adrenal gland are surrounded by two layers of fat (the perirenal and pararenal fat) and the renal fascia. Each adult kidney weighs between 125 and 170 grams in males and between 115 and 155 grams in females.^[5] The left kidney is typically slightly larger than the right.^[6]

Left kidney

Structure

1. Renal pyramid • 2. Interlobular artery • 3. Renal artery • 4. Renal vein 5. Renal hilum • 6. Renal pelvis • 7. Ureter • 8. Minor calyx • 9. Renal capsule • 10. Inferior renal capsule • 11. Superior renal capsule • 12. Interlobular vein • 13. Nephron • 14. Minor calyx • 15. Major calyx • 16. Renal papilla • 17. Renal column

The kidney has a bean-shaped structure; each kidney has a convex and concave surface. The concave surface, the renal hilum, is the point at which the renal artery enters the organ, and the renal vein and ureter leave. The kidney is surrounded by tough fibrous tissue, the renal capsule, which is itself surrounded by perinephric fat, renal fascia (of Gerota) and paranephric fat. The anterior (front) border of these tissues is the peritoneum, while the posterior (rear) border is the transversalis fascia.

The superior border of the right kidney is adjacent to the liver; and the spleen, for the left kidney. Therefore, both move down on inhalation.

The kidney is approximately 11–14 cm in length, 6 cm wide and 4 cm thick.

The substance, or parenchyma, of the kidney is divided into two major structures: superficial is the renal cortex and deep is the renal medulla. Grossly, these structures take the shape of 8 to 18 cone-shaped renal lobes, each containing renal cortex surrounding a portion of medulla called a renal pyramid (of Malpighi).^[5] Between the renal pyramids are projections of cortex called renal columns (of Bertin). 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, located in the cortex, which is followed by a renal tubule that passes from the cortex deep into the medullary pyramids. Part of the renal cortex, a medullary ray is a collection of renal tubules that drain into a single collecting duct.

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, which becomes the ureter.

Blood supply

3D-rendered computed tomography, showing renal arteries and veins.

The kidneys receive blood from the renal arteries, left and right, which branch directly from the abdominal aorta. Despite their relatively small size, the kidneys receive approximately 20% of the cardiac output.^[5]

Each renal artery branches into segmental arteries, dividing further into interlobar arteries which penetrate 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.

The interstitum (or interstitium) is the functional space in the kidney beneath the individual filters (glomeruli) which are rich in blood vessels. The interstitum absorbs fluid recovered from urine. Various conditions can lead to scarring and congestion of this area, which can cause kidney dysfunction and failure.

After filtration occurs the blood moves through a small network of 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 vein exiting the kidney for transfusion for blood.

Histology

Microscopic photograph of the renal medulla

Microscopic photograph of the renal cortex

Renal histology studies the structure of the kidney as viewed under a microscope. Various distinct cell types occur in the kidney, including:

Kidney glomerulus parietal cell
Kidney glomerulus podocyte
Kidney proximal tubule brush border cell
Loop of Henle thin segment cell
Thick ascending limb cell
Kidney distal tubule cell
Kidney collecting duct cell
Interstitial kidney cells
Renal arteries and its branches

       The renal artery enters into the kidney at the level of 1st lumber vertebra just below the

superior mesentric artery, as it enters into the kidney it is divided in its branches, 1st the segmental artery and then segmental artery divided into 2 or 3 lobar arteries and it further divided into interlobar arteries which further divide into arcuate artery which leeds into the interlobular artery,which form affrent artioles(go into) it form glomerulous(network of cappelries closed in bowman capsule),then from here efferent artiole(go back) leaves the glomerolous and divide into pritubolar capplries ,then that pritunolar leeds into the interlobular veins and then into arcuate vein and then into interlobar vein,which runs into lobar vein ,which opens into the segmental vein and which drains into the RENAL VEIN and then from it blood moves into the inferior vena cava.

Innervation

The kidney and nervous system communicate via the renal plexus, whose fibers course along the renal arteries to reach the kidney.^[7] Input from the sympathetic nervous system triggers vasoconstriction in the kidney, thereby reducing renal blood flow.^[7] The kidney is not thought to receive input from the parasympathetic nervous system.^[7] Sensory input from the kidney travels to the T10-11 levels of the spinal cord and is sensed in the corresponding dermatome.^[7] Thus, pain in the flank region may be referred from the kidney.^[7]

Functions

Main article: Renal physiology

The kidney participates in whole-body homeostasis, regulating acid-base balance, electrolyte concentrations, extracellular fluid volume, and regulation of blood pressure. The kidney accomplishes these homeostatic functions both independently and in concert with other organs, particularly those of the endocrine system. Various endocrine hormones coordinate these endocrine functions; these include renin, angiotensin II, aldosterone, antidiuretic hormone, and atrial natriuretic peptide, among others.

Kidneys

Many of the kidney's functions are accomplished by relatively simple mechanisms of filtration, reabsorption, and secretion, which take place in the nephron. Filtration, which takes place at the renal corpuscle, is the process by which cells and large proteins are filtered from the blood to make an ultrafiltrate that eventually becomes urine. The kidney generates 180 liters of filtrate a day, while reabsorbing a large percentage, allowing for the generation of only approximately 2 liters of urine. Reabsorption is the transport of molecules from this ultrafiltrate and into the blood. Secretion is the reverse process, in which molecules are transported in the opposite direction, from the blood into the urine.

Excretion of wastes

The kidneys excrete a variety of waste products produced by metabolism. These include the nitrogenous wastes called "urea", from protein catabolism, as well as uric acid, from nucleic acid metabolism. Formation of urine is also the function of the kidney.

Acid-base homeostasis

Main article: Acid-base homeostasis

Two organ systems, the kidneys and lungs, maintain acid-base homeostasis, which is the maintenance of pH around a relatively stable value. The lungs contribute to acid-base homeostasis by regulating carbonic gas (CO₂) concentration. The kidneys have two very important roles in maintaining the acid-base balance: to reabsorb bicarbonate from urine, and to excrete hydrogen ions into urine

Osmolality regulation

Any significant rise in plasma osmolality is detected by the hypothalamus, which communicates directly with 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.

ADH binds to principal cells in the collecting duct that translocate aquaporins to the membrane, allowing water to leave the normally impermeable membrane and be reabsorbed into the body by the vasa recta, thus increasing the plasma volume of the body.

There are two systems that create a hyperosmotic medulla and thus increase the body plasma volume: Urea recycling and the 'single effect.'

Urea is usually excreted as a waste product from the kidneys. However, when plasma blood volume is low and ADH is released the aquaporins that are opened are also permeable to urea. This allows urea to leave the collecting duct into the medulla creating a hyperosmotic solution that 'attracts' water. Urea can then re-enter the nephron and be excreted or recycled again depending on whether ADH is still present or not.

The 'Single effect' describes the fact that the ascending thick limb of the loop of Henle is not permeable to water but is permeable to NaCl. This allows for a countercurrent exchange system whereby the medulla becomes increasingly concentrated, but at the same time setting up an osmotic gradient for water to follow should the aquaporins of the collecting duct be opened by ADH.

Blood pressure regulation

Main articles: Blood pressure regulation and Renin-angiotensin system

Long-term regulation of blood pressure predominantly depends upon the kidney. This primarily occurs through maintenance of the extracellular fluid compartment, the size of which depends on the plasma sodium concentration. Although the kidney cannot directly sense blood pressure, changes in the delivery of sodium and chloride to the distal part of the nephron alter the kidney's secretion of the enzyme renin. When the extracellular fluid compartment is expanded and blood pressure is high, the delivery of these ions is increased and renin secretion is decreased. Similarly, when the extracellular fluid compartment is contracted and blood pressure is low, sodium and chloride delivery is decreased and renin secretion is increased in response.

Renin is the first in a series of important chemical messengers that comprise 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 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.

Hormone secretion

The kidneys secrete a variety of hormones, including erythropoietin, and the enzyme 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 the bone marrow. Calcitriol, the activated form of vitamin D, promotes intestinal absorption of calcium and the renal reabsorption of phosphate. Part of the renin-angiotensin-aldosterone system, renin is an enzyme involved in the regulation of aldosterone levels..

Development

Main article: Kidney development

The mammalian kidney develops from intermediate mesoderm. Kidney development, also called nephrogenesis, proceeds through a series of three successive phases, each marked by the development of a more advanced pair of kidneys: the pronephros, mesonephros, and metanephros.^[8]

Evolutionary adaptation

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.^[9]

Related terms

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).^[10] For example, surgical removal of the kidney is a nephrectomy, while a reduction in kidney function is called renal dysfunction.

Diseases and disorders

Main article: Nephropathy

Congenital

Congenital hydronephrosis
Congenital obstruction of urinary tract
Duplex kidneys, or double kidneys, occur in approximately 1% of the population. This occurrence normally causes no complications, but can occasionally cause urine infections.^[11]^[12]
Duplicated ureter occurs in approximately one in 100 live births
Horseshoe kidney occurs in approximately one in 400 live births
Polycystic kidney disease
- Autosomal dominant polycystic kidney disease afflicts patients later in life. Approximately one in 1000 people will develop this condition
- Autosomal recessive polycystic kidney disease is far less common, but more severe, than the dominant condition. It is apparent in utero or at birth.
Renal agenesis. Failure of one kidney to form occurs in approximately one in 750 live births. Failure of both kidneys to form is invariably fatal.
Renal dysplasia
Unilateral small kidney
Multicystic dysplastic kidney occurs in approximately one in every 2400 live births
Ureteropelvic Junction Obstruction or UPJO; although most cases appear congenital, some appear to be an acquired condition^[13]

Acquired

Drawing of an enlarged kidney by John Hunter.

Diabetic nephropathy
Glomerulonephritis
Hydronephrosis is the enlargement of one or both of the kidneys caused by obstruction of the flow of urine.
Interstitial nephritis

Kidney stones (nephrolithiasis) are a relatively common and particularly painful disorder.
Kidney tumors
- Wilms tumor
- Renal cell carcinoma
Lupus nephritis
Minimal change disease
In nephrotic syndrome, the glomerulus has been damaged so that a large amount of protein in the blood enters the urine. Other frequent features of the nephrotic syndrome include swelling, low serum albumin, and high cholesterol.
Pyelonephritis is infection of the kidneys and is frequently caused by complication of a urinary tract infection.
Renal failure
- Acute renal failure
- Stage 5 Chronic Kidney Disease

Kidney Failure

Main article: Renal failure

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, is indicated when the glomerular filtration rate has fallen very low or if the renal dysfunction leads to severe symptoms.

In other animals

A pig's kidney opened.

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 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 the adult.^[14]

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.^[14]

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.^[14]

Birds have relatively large, elongated kidneys, each of which 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.^[14]

The human kidney is fairly typical of that of mammals. Distinctive features of the mammalian kidney, in comparison with that of other vertebrates, include the presence of the renal pelvis and renal pyramids, and of 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 the multilobed reniculate kidneys of cetaceans.^[14]

History

The Latin term renes is related to the English word "reins", a synonym for the kidneys in Shakespearean English (e.g. Merry Wives of Windsor 3.5), which was also the time the King James Version was translated. Kidneys were once popularly regarded as the seat of the conscience and reflection,^[15]^[16] and a number of verses in the Bible (e.g. Ps. 7:9, Rev. 2:23) state that God searches out and inspects the kidneys, or "reins", of humans. Similarly, the Talmud (Berakhoth 61.a) states that one of the two kidneys counsels what is good, and the other evil.

Animal kidneys as food

Hökarpanna, Swedish pork and kidney stew

The kidneys of animals can be cooked and eaten by humans (along with other offal).

Kidneys are usually grilled or sautéed, but in more complex dishes they are stewed with a sauce that will improve their flavor. In many preparations, kidneys are combined with pieces of meat or liver, as in mixed grill or meurav Yerushalmi. Among the most reputed kidney dishes, the British steak and kidney pie, the Swedish hökarpanna (pork and kidney stew), the French rognons de veau sauce moutarde (veal kidneys in mustard sauce) and the Spanish riñones al Jerez (kidneys stewed in sherry sauce), deserve special mention.^[17]

References

^ Cotran, RS S.; Kumar, Vinay; Fausto, Nelson; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease. St. Louis, MO: Elsevier Saunders. ISBN 0-7216-0187-1.
^ "Kidneys Location Stock Illustration". http://www.indexedvisuals.com/scripts/ivstock/pic.asp?id=118-100.
^ [1]^{[dead link]}
^ Bålens ytanatomy (Superficial anatomy of the trunk). Anca Dragomir, Mats Hjortberg and Godfried M. Romans. Section for human anatomy at the Department of medical biology, Uppsala university, Sweden.
^ ^a ^b ^c Walter F., PhD. Boron (2004). Medical Physiology: A Cellular And Molecular Approach. Elsevier/Saunders. ISBN 1-4160-2328-3.
^ Glodny B, Unterholzner V, Taferner B, et al. (2009). "Normal kidney size and its influencing factors - a 64-slice MDCT study of 1.040 asymptomatic patients". BMC Urology 9: 19. doi:10.1186/1471-2490-9-19. PMC 2813848. PMID 20030823. http://www.biomedcentral.com/1471-2490/9/19.
^ ^a ^b ^c ^d ^e Bard, Johnathan; Vize, Peter D.; Woolf, Adrian S. (2003). The kidney: from normal development to congenital disease. Boston: Academic Press. p. 154. ISBN 0-12-722441-6. http://books.google.com/?id=ctOm-cPwo60C&pg=PA154.
^ Bruce M. Carlson (2004). Human Embryology and Developmental Biology (3rd ed.). Saint Louis: Mosby. ISBN 0-323-03649-X.
^ Al-kahtani, M. A.; C. Zuleta, E. Caviedes-Vidal, and T. Garland, Jr. (2004). "Kidney mass and relative medullary thickness of rodents in relation to habitat, body size, and phylogeny". Physiological and Biochemical Zoology 77 (3): 346–365. doi:10.1086/420941. PMID 15286910. http://www.biology.ucr.edu/people/faculty/Garland/Al-kahtaniEA2004.pdf.
^ Maton, Anthea; Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright (1993). Human Biology and Health. Englewood Cliffs, New Jersey, USA: Prentice Hall. ISBN 0-13-981176-1.
^ Sample, Ian (2008-02-19). "How many people have four kidneys?". The Guardian (London). http://www.guardian.co.uk/society/2008/feb/19/health.
^ "Girl's Kidneys Fail, But Doctors Find Double Valves, Saving Her Life". Abcnews.go.com. 2010-05-18. http://abcnews.go.com/Health/girls-kidneys-fail-doctors-find-double-valves-saving/story?id=10668525. Retrieved 2011-01-03.
^ Stephen Jones, J.; Inderbir S. Gill, Raymond Rackley (2006). Operative Urology at the Cleveland Clinic. Andrew C. Novick, Inderbir S. Gill, Eric A. Klein, Jonathan H. Ross (eds.). Totowa, NJ: Humana Press. ISBN 978-1-58829-081-6. http://www.springerlink.com/content/p483835241230k88/. Retrieved 2010-10-09.
^ ^a ^b ^c ^d ^e Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 367–376. ISBN 0-03-910284-X.
^ The Patient as Person: Explorations in Medical Ethics p. 60 by Paul Ramsey, Margaret Farley, Albert Jonsen, William F. May (2002)
^ History of Nephrology 2 p. 235 by International Association for the History of Nephrology Congress, Garabed Eknoyan, Spyros G. Marketos, Natale G. De Santo - 1997; Reprint of American Journal of Nephrology; v. 14, no. 4-6, 1994.
^ Rognons dans les recettes (French)

External links

Wikimedia Commons has media related to: Kidneys

Human systems and organs

TA 2–4:
MS

Skeletal system	Bone (Carpus · Collar bone (clavicle) · Thigh bone (femur) · Fibula · Humerus · Mandible · Metacarpus · Metatarsus · Ossicles · Patella · Phalanges · Radius · Skull (cranium) · Tarsus · Tibia · Ulna · Rib · Vertebra · Pelvis · Sternum) · Cartilage

Joints	Fibrous joint · Cartilaginous joint · Synovial joint

Muscular system	Muscle · Tendon · Diaphragm

TA 5–11:
splanchnic/
viscus

mostly
Thoracic

Respiratory system	URT (Nose, Nasopharynx, Larynx) · LRT (Trachea, Bronchus, Lung)

mostly
Abdominopelvic

Digestive system+ adnexa	Mouth (Salivary gland, Tongue) · upper GI (Oropharynx, Laryngopharynx, Esophagus, Stomach) · lower GI (Small intestine, Appendix, Colon, Rectum, Anus) · accessory (Liver, Biliary tract, Pancreas)

GU: Urinary system	Kidney · Ureter · Bladder · Urethra

GU: Reproductive system	Female (Uterus, Vulva, Ovary, Placenta) · Male (Scrotum, Penis, Prostate, Testicle, Seminal vesicle)

Endocrine system

Pituitary · Pineal · Thyroid · Parathyroid · Adrenal · Islets of Langerhans

TA 12–16

Circulatory system

Cardiovascular system	peripheral (Artery, Vein, Lymphatic vessel) · Heart

Lymphatic system	primary (Bone marrow, Thymus) · secondary (Spleen, Lymph node)

Nervous system

(Brain, Spinal cord, Nerve) · Sensory system (Ear, Eye)

Integumentary system

Skin · Subcutaneous tissue · Breast (Mammary gland)

Blood
(Non-TA)

Myeloid	Myeloid immune system

Lymphoid	Lymphoid immune system

General anatomy: systems and organs, regional anatomy, planes and lines, superficial axial anatomy, superficial anatomy of limbs

Anatomy: urinary system (TA A08, TH H3.06, GA 11.1215)

Abdomen

Kidneys

Layers	Renal fascia Renal capsule Renal cortex Renal column Renal medulla Renal sinus Renal pyramids medullary interstitium Renal lobe Cortical lobule Medullary ray Nephron

Intrarenal arteries	Renal artery Segmental arteries Interlobar arteries Arcuate arteries Interlobular arteries Afferent arterioles

Renal tubule	Renal corpuscle Glomerulus Bowman's capsule Proximal tubule Loop of Henle Descending Thin ascending Thick ascending Distal convoluted tubule Connecting tubule Collecting ducts aka Duct of Belini Renal papilla Minor calyx Major calyx Renal pelvis

Intrarenal veins	Efferent arterioles Peritubular capillaries/Vasa recta Arcuate vein Interlobar veins Renal vein

JGA	Macula densa Juxtaglomerular cells Mesangium/Extraglomerular mesangial cell

Filtration	Glomerular basement membrane Podocyte Filtration slits Mesangium/Intraglomerular mesangial cell Tubular fluid

Ureters

Pelvis

Bladder	Apex Uvula Neck Median umbilical ligament Muscular layer Trigone Detrusor Mucosa Submucosa

Urethra	Urethral sphincters External sphincter muscle of male urethra External sphincter muscle of female urethra Internal sphincter muscle of urethra

M: URI

anat/phys/devp/cell

noco/acba/cong/tumr, sysi/epon, urte

proc/itvp, drug (G4B), blte, urte

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

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Translations:

Kidney

Top

Dansk (Danish)
n. - nyre

idioms:

kidney bean havebønne, snittebønne, krybbønne, pralbønne
kidney machine dialysemaskine
kidney stone nyresten

Nederlands (Dutch)
nier

Français (French)
n. - (Culin) rognon, (Anat) rein, (fig) acabit

idioms:

kidney bean haricot rouge
kidney machine (Méd) rein artificiel, dialyseur, (être) en hémodialyse, (être) en épuration extrarénale, (être) sous rein artificiel
kidney stone calcul rénal

Deutsch (German)
n. - Niere

idioms:

kidney bean Weiße Bohne, Feuerbohne
kidney machine künstliche Niere, Dialysegerät
kidney stone Nierenstein

Ελληνική (Greek)
n. - (ανατ.) νεφρό(ς)

idioms:

kidney bean κοινό φασόλι
kidney machine μηχάνημα τεχνητού νεφρού
kidney stone πέτρα του νεφρού

Italiano (Italian)
rene

idioms:

kidney bean fagiolo marrone-purpureo, fagiolo della regina
kidney machine rene artificiale
kidney stone calcolo renale

Português (Portuguese)
n. - rim (m) (Anat.), índole (f) (coloq.), tipo (m) (coloq.)

idioms:

kidney bean feijão (m)
kidney machine máquina (f) de hemodiálise (Med.)
kidney stone pedra (f) no rim (Med.), cálculo (m) renal (Med.)

Русский (Russian)
почка, темперамент, склад характера

idioms:

kidney bean фасоль обыкновенная
kidney machine искусственная почка
kidney stone галька, нефрит

Español (Spanish)
n. - riñón, temperamento, especie

idioms:

kidney bean frijol, poroto, judía, alubia, alubia pinta
kidney machine riñón artificial
kidney stone cálculo renal

Svenska (Swedish)
n. - njure, slag, sort

中文（简体）(Chinese (Simplified))
肾, 性格, 个性

idioms:

kidney bean 菜豆, 四季豆, 云豆
kidney machine 人工肾血液透析器
kidney stone 肾结石

中文（繁體）(Chinese (Traditional))
n. - 腎, 性格, 個性

idioms:

kidney bean 菜豆, 四季豆, 雲豆
kidney machine 人工腎血液透析器
kidney stone 腎結石

한국어 (Korean)
n. - 신장, 기질, 종류

日本語 (Japanese)
n. - 腎臓, 気質, 性質

idioms:

kidney bean いんげん豆, インゲンマメ
kidney machine 人工腎臓
kidney stone 腎臓形の小石, 軟玉, 腎石

العربيه (Arabic)
‏(الاسم) كليه الإنسان‏

עברית (Hebrew)
n. - ‮כליה, סוג, טבע, מזג‬

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