Malphigian is an attribute to several anatomical structures Malpighian corpuscle , which in turn may refer to Renal corpuscle s &mdash the initial filtering component of nephron s in the kidney s splenic lymphoid nodules , or White nodules &mdash follicles in the white pulp of the spleen , containing many lymphocyte s Malpighian layer of the skin, a term with various definitions Malpighian tubule system , a type of excretory and osmoregulatory system found in some Uniramia Insects and Myriapoda , arachnids and tardigrades. References reflist disambig ... more details
Expert subject medicine date November 2008 Unreferenced date October 2008 Terminal cisternae are enlarged areas of the sarcoplasmic reticulum surrounding the transverse tubules . These discrete regions within the muscle cell store calcium increasing the capacity of the sarcoplasmic reticulum to release calcium and release it when an action potential courses down the transverse tubules, eliciting muscle contraction . Because terminal cisternae ensure rapid calcium delivery, they are well developed in muscles that contract quickly, such as fast twitch skeletal muscle . The T tubules plus adjacent terminal cisternae create a triad. In cardiac muscle, adjacent to the intercalated disks, one would find a diad which consists of a T tubule adjacent to a single terminal cisterna. Terminal cisternae are pairs of transversely oriented tubules of the sarcoplasmic reticulum occurring at regular intervals in skeletal muscle fibers together with an intermediate T tubule they make up a triad. Category Anatomy articles needing expert attention Category Anatomy anatomy stub sv Terminala cisternae ... more details
working of osmotic diuretics The renal proximal tubule is the primary site of action of osmotic diuretics. Normally, water molecules follow Na sup sup out of the proximal tubule, resulting in Na sup ... in the tubule. Since the luminal membrane is quite leaky to Na sup sup , this causes a high back leak of Na sup sup into the tubule. Na sup sup is normally followed by K sup sup and Cl sup sup out of the proximal tubule. When there is high back leak of Na sup sup , these electrolytes stay in the tubule ... more details
area to become epithelial tubules called mesonephric tubule s. Each mesonephric tubule receives ... kidney glomerulus of the definitive nephron . The mesonephric tubule forms a capsule around the capillary tuft, allowing for filtration of blood. This filtrate flows through the mesonephric tubule ... into the renal tubule s. As the renal tubules grow, they come into contact and join with connecting tubule s of the collecting duct system, forming a continuous passage for flow from the renal tubule to the collecting duct. Simultaneously, precursors of vascular endothelial cells begin to take ... more details
Infobox Anatomy Name PAGENAME Latin GraySubject GrayPage Image Germinal epithelium testicle.svg Caption Germinal epithelium of the testicle . 1 basal lamina , 2 spermatogonia , 3 spermatocyte 1st order, 4 spermatocyte 2nd order, 5 spermatid , 6 mature spermatid, 7 Sertoli cell , 8 tight junction blood testis barrier Image2 Caption2 Precursor System Artery Vein Nerve Lymph MeshName MeshNumber DorlandsPre DorlandsSuf The blood testis barrier abbreviated as BTB is a physical barrier between the blood vessel s and the seminiferous tubule s of the animal testicle testes . The name blood testis barrier is misleading in a sense that it is not a blood organ barrier sensu strictu, but is formed between Sertoli cell s of the seminiferous tubule and as such isolates the further developed stages of germ cells from the blood. A more correct term is the Sertoli cell barrier SCB . The barrier is formed by tight junctions, adherens junctions and gap junctions between the Sertoli cell s, which are sustentacular cell s supporting cells of the seminiferous tubules , and divides the seminiferous tubule in a basal compartment outer side of the tubule, in contact with blood and lymph and an adluminal compartment inner side of the tubule, isolated from blood and lymph . The presence of the SCB allows Sertoli cell to control the adluminal environment in which germ cells spermatocytes, spermatids and sperm develop by influencing the chemical composition of the luminal fluid. The barrier also prevents passage of cytotoxicity cytotoxic agents bodies or substances that are toxicity toxic to cell biology cell s into the seminiferous tubules. Auto immune response The blood testes barrier can be damaged by trauma to the testes including torsion or impact , by surgery or as a result of vasectomy . When the blood testes barrier is breached, and sperm enters the bloodstream, the immune system mounts an autoimmune response against the sperm. The anti sperm antibody antibodies generated by the immune ... more details
, lead to an increased risk of bacterial infection in the scarred renal tissues and functional tubule ... cell disease and likely results from infarctive episodes in the renal medulla. Functional tubule ... in vasa recta blood flow, combined with ischemic tubule injury. This concentrating defect places these patients ... also occurs in individuals with sickle trait. Other tubule defects involve potassium and hydrogen ion ... more details
Unreferenced stub auto yes date December 2009 Confusing date February 2007 In physiology , reabsorption or tubular reabsorption is the flow of glomerular filtrate from the proximal tubule of the nephron into the peritubular capillaries , or from the urine into the blood. It is termed reabsorption because this is technically the second time that the nutrients in question are being absorbed into the blood, the first time being from the small intestine into the villi. This happens as a result of sodium transport from the lumen into the blood by the Na K ATPase in the basolateral membrane of the epithelial cell s. Thus, the glomerular filtrate becomes more Concentration concentrated , which is one of the steps in forming urine . In this way, many useful solution solutes primarily glucose and amino acid s , salt s and water that have passed in the proximal tubule through the Bowman s capsule , return in the Circulatory system circulation . These solutes are reabsorbed Tonicity isotonically , in that the osmotic potential of the fluid leaving the proximal tubule is the same as that of the initial glomerular filtrate. However, glucose, amino acids, inorganic phosphate , and some other solutes are reabsorbed via secondary active transport through Symporter cotransport channels driven by the sodium gradient out of the nephron. Renin Angiotensin System 1. The kidneys sense low blood pressure. 2. Release renin into the blood. 3. Renin causes production of Angiotensin I. 4. Angiotensin Converting Enzyme ACE converts Angiotensin I to Angiotensin II. 5. Angiotensin II stimulates the release of Aldosterone, ADH, and thirst. 6. Aldosterone causes kidneys to reabsorb sodium. ADH increases the uptake of water. 7. Water follows sodium. 8. Blood volume goes up, therefore blood pressure goes up. Category Renal physiology Anatomy stub ru ... more details
Infobox Embryology Name PAGENAME Latin blastema metanephrogenicum GraySubject GrayPage Image Caption Image2 Caption2 System Days 35 CarnegieStage 14 Precursor Wolffian duct GivesRiseTo nephron Bowman s capsule , connecting tubule , distal convoluted tubule , glomerulus , loop of Henle , proximal convoluted tubule , but not collecting duct MeshName MeshNumber Code Terminologia Embryologica TE E5.6.3.2.0.0.1 The metanephrogenic blastema or metanephric blastema or metanephric mesenchyme , or metanephric mesoderm is one of the two embryo logical structures that give rise to the kidney the other is the ureteric bud . The metanephric blastema mostly develops into nephrons , but can also form parts of the collecting duct system . The system of tissue induction between the ureteric bud and the metanephric blastema is a reciprocal control system. GDNF, gonadal derived neurotrophic factor, is produced by the metanephric blastema and is essential in binding to the Ret receptor on the ureteric bud, which bifurcates and coalesces as a result to form the renal pelvis, major and minor calyces and collecting ducts. Mutations in the EYA1 gene, which is a GDNF transcription factor, lead to the renal abnormalities of BOR syndrome branchio oto renal syndrome . See also Mesenchyme Metanephros Blastema Kidney development External links EmbryologySwiss turinary urinhaute01 EmbryologyUNC genital 017a http sprojects.mmi.mcgill.ca embryology ug Kidney Stuff Drawings 2ureter.GIF Diagram at mcgill.ca 1 http sprojects.mmi.mcgill.ca embryology ug Kidney Stuff Normal Development Mature Kidney2.html Diagram at mcgill.ca 2 cite journal author Qiao J, Cohen D, Herzlinger D title The metanephric blastema differentiates into collecting system and nephron epithelia in vitro. journal Development volume 121 issue 10 pages 3207 14 year 1995 pmid 7588055 developmental biology stub Development of urinary and reproductive systems Category Embryology ... more details
causes an increased absorption of sodium ions into the vasa recta at the proximal tubule . Because of this increased absorption, less NaCl is present at the distal tubule where the macula densa is located ... more details
orphan date August 2008 Osmotic nephrosis refers to structural changes that occur at the cellular level in the human kidney . Cell biology Cells , primarily of the straight proximal tubule , swell due to the formation of large vacuole s in the cytoplasm . These vacuoles occur in the presence of large amounts of certain solution solutes circulating in the tubules. However, despite the condition s name, the solutes do not cause change through osmotic forces but through pinocytosis . Once inside the cytoplasm, pinocytic vacuoles combine with each other and with lysosome s to form large vacuoles that appear transparent under microscopic examination. There may be no symptomatic presentation with this condition, or it may confused with other nephrotic conditions such as Tubular calcineurin inhibitor toxicity. Affected cells of the proximal tubule may be passed in the urine , but a kidney biopsy is the only sure way to make a diagnosis. Responsible exogenous solutes include sucrose containing IVIg, mannitol , dextran , contrast dye, and hydroxyethyl starch . Prevention includes standard preventions for iatrogenic kidney damage. Osmotic nephrosis is usually reversible but can lead to chronic renal failure . References Dickenmann M, Oettl T, & Mihatsch MJ. 2008 Osmotic nephrosis Acute kidney injury with accumulation of proximal tubular lysosomes due to administration of exogenous solutes. American Journal of Kidney Diseases, 51 3 , 491 503. Retrieved 9 Mar 2008 from MDConsult database. External links http www.nature.com ki journal v70 n10 fig tab 5001737f1.html Image of osmotic nephrosis histopathologic finding Category Nephrology ... more details
Unreferenced stub auto yes date December 2009 Image Gray1150.png thumb 350px right Cross section of the epithelium of a seminiferous tubule showing various stages of spermatocyte development Image Gray7.png thumb 350px right Scheme showing analogies in the process of maturation of the ovum and the development of the spermatids young spermatozoa . Spermatidogenesis is the creation of spermatid s from spermatocytes secondary spermatocytes during spermatogenesis . Secondary spermatocytes produced earlier rapidly enter meiosis meiosis II and divide to produce haploid spermatid s. The brevity of this stage means that secondary spermatocytes are rarely seen in histological preparations. Male reproductive system Category Male reproductive system Cell biology stub ru ... more details
Image Microvilli Duodenum.JPG thumb Duodenum with brush border microvilli microvillus Image Normal Villus Illustration.png thumb right 210px Illustration of the brush border membrane of small intestinal villi A brush border or striated border or brush border membrane is the name for the microvilli covered surface of simple cuboidal epithelium and simple columnar epithelium cells found in certain locations of the body. Microvilli are approximately 100 nanometers in diameter and their length varies from approximately 100 to 2,000 nanometers in length. Because individual microvilli are so small and are tightly packed in the brush border, individual microvilli can only be resolved using electron microscope s ref BUHistology 21901loa ref with a light microscope they can usually only be seen collectively as a fuzzy fringe at the surface of the epithelium. This fuzzy appearance gave rise to the term brush border , as early anatomists noted that this structure appeared very much like the bristles of a paintbrush. Brush border cells are found in two main locations The small intestine tract This is where absorption small intestine absorption takes place. ref BUHistology 12202loa ref ref BUHistology 11703loa ref ref http www.pathguy.com histo 085.htm Basic Histology Intestinal Columnar Epithelium Bot generated title ref The brush borders of the intestinal lining are the site of terminal carbohydrate digestions. The microvilli that constitute the brush border have enzymes for this final part of digestion anchored into their apical plasma membrane as integral membrane proteins. These enzymes are found near to the transporters that will then allow absorption of the digested nutrients. The kidney Here the brush border is useful in distinguishing the Proximal convoluted tubule proximal tubule which possesses the brush border from the Distal convoluted tubule distal tubule which does not . ref OklahomaHistology 35 19 Kidney ref ref KansasHistology urinary renal13 Tubules ref The bru ... more details
Infobox Vein Name Interlobular veins Latin venae interlobulares renis GraySubject 254 GrayPage 1224 Image Gray1128.png Caption Scheme of renal tubule and its vascular supply. Image2 Caption2 DrainsFrom Efferent arteriole DrainsTo Arcuate vein Artery Interlobular arteries MeshName MeshNumber DorlandsPre v 05 DorlandsSuf 12850670 The venae stellatae join to form the interlobular veins , which pass inward between the rays , receive branches from the plexuses around the convoluted tubules , and, having arrived at the bases of the renal pyramids , join with the venae rectae . External links eMedicineDictionary interlobular veins of kidney BUHistology 16015loa Urinary System kidney, H&E, interlobular artery and vein Gray s Kidney Category Kidney anatomy circulatory stub ca V nula interlobel lar del rony ... more details
distinguish Dyad for the chemical compound abbreviated DIAD Diisopropyl azodicarboxylate The diad is a structure in the cardiac myocyte located at the sarcomere Z line. It is composed of a single t tubule paired with a terminal cisterna of the sarcoplasmic reticulum . The diad plays an important role in excitation contraction coupling by juxtaposing an inlet for the action potential near a source of Ca sup 2 sup ions. This way, the wave of depolarization can be coupled to calcium mediated cardiac muscle Muscle contraction contraction via the sliding filament mechanism. References cite book author Stanton, Bruce A. Berne, Robert M. Levy, Matthew N. Koeppen, Bruce M. title Physiology publisher Mosby location St. Louis year 2005 pages isbn 0 323 03390 3 oclc doi Category Human cells anatomy stub sr ... more details
context date April 2010 The thin segment is a segment of the nephron , which consists of thin descending limb of loop of Henle thin ascending limb of loop of Henle Histology Loop of Henle thin segment cell redirect here The basement membrane of the thin limb in humans has very uniform nodular thickenings that form a network that surrounds the tubule and acts as a support structure that is homologous to the collenchyma in plants. Smith, RA et al Arch Pathol Lab Med Vol 108, May 1984 have designated these nodules Belliveau Bodies after Robert Belliveau the pathologist who originally described these structures. The epithelium is Simple squamous epithelium . ref https histo.life.illinois.edu histo lab kidney kidney.htm University of Illinois College of Medicine ref References references genitourinary stub Category Kidney anatomy ... more details
The Cl formate exchanger is a transport protein present in the kidney ref http www.pnas.org cgi content abstract 82 18 6362 Chloride Formate Exchange with Formic Acid Recycling A Mechanism of Active Chloride Transport across Epithelial Membranes Lawrence P. Karniski and Peter S. Aronson ref , where it functions in the renal chloride reabsorption . It is also present in vascular smooth muscle and cardiac muscle ref http circres.ahajournals.org cgi content abstract 74 1 48 Presence of chloride formate exchange in vascular smooth muscle and cardiac cells M Soleimani and RL Howard. Department of Medicine, Indiana University School of Medicine, Indianapolis 46202 5116. ref . The true molecular nature of the protein is unknown ref http www.pnas.org cgi reprint 141241098v1.pdf renal proximal tubule cells Identification of a chloride formate ... ref . References reflist Membrane transport proteins Ion pumps Category Transport proteins ... more details
Renal reabsorption of chloride chloride Cl sup sup is a part of renal physiology , in order not to lose too much chloride in the urine . Overview table Class wikitable width 100 Characteristics of Cl sup sup reabsorption rowspan 2 Characteristic colspan 3 proximal tubule colspan 3 loop of Henle rowspan 2 Distal convoluted tubule colspan 4 Collecting duct system S1 S2 S3 Descending limb of loop of Henle descending limb thin ascending limb of loop of Henle thin ascending limb thick ascending limb of loop of Henle thick ascending limb connecting tubule initial collecting tubule cortical collecting ducts medullary collecting ducts reabsorption reabsorption m Mole unit moles day Concentration m Concentration Molarity M 115 ref name boron780 135 ref name boron780 Membrane potential electrical driving force m Volt V 3 ref name boron777 cite book author Walter F., PhD. Boron title Medical Physiology A Cellular And Molecular Approaoch publisher Elsevier Saunders location year 2005 pages isbn 1 4160 2328 3 oclc doi Page 777 ref 3 ref name boron777 15 ref name boron777 5 to 5 ref name boron777 40 ref name boron777 chemical potential chemical driving force m Volt V Electrochemical potential electrochemical driving force m Volt V positive ref name boron779 cite book author Walter F., PhD. Boron title Medical Physiology A Cellular And Molecular Approaoch publisher Elsevier Saunders location year 2005 pages isbn 1 4160 2328 3 oclc doi Page 779 ref apical membrane apical transport proteins passively ref name boron779 Cl formate exchanger Cl oxalate exchanger chloride bicarbonate exchanger Cl sup sup HCO sub 3 sub sup sup exchanger Chloride hydroxyl exchanger Cl sup sup OH sup sup exchanger Na K 2Cl cotransporter ref name boron780 Na Cl cotransporter ref name boron780 principal cell s paracellular ily ref name boron780 basolateral membrane basolateral transport proteins chloride channel s ref name boron780 Cl K cotransporter ref name boron780 cite book author Walter F., PhD. Boron t ... more details
Solvent drag , also known as bulk transport , is a phenomenon primarily in renal physiology , but it also occurs in gastrointestinal physiology. It is when Solution solute s in the ultrafiltrate are transported back from the renal tubule by the flow of water rather than specifically by ion pumps or other membrane transport protein s. ref name boron791 cite book author Walter F., PhD. Boron title Medical Physiology A Cellular And Molecular Approach publisher Elsevier Saunders location year pages isbn 1 4160 2328 3 oclc doi Page 791 ref It generally occurs in the paracellular , rather than transcellular , pathway across the tubular cell s. It is seen e.g. in the passive transport in renal sodium reabsorption , renal chloride reabsorption as well as renal urea handling . References reflist renal physiology Category Renal physiology de Solvent Drag ... more details
Renal urea handling is the part of renal physiology that deals with the reabsorption and secretion of urea . Movement of large amounts of urea across cell membranes is made possible by urea transporter proteins. Urea allows the kidney s to create hyperosmotic urine urine that has more ions in it is more concentrated than that same person s blood plasma . Preventing the loss of water in this manner is important if the person s body must save water in order to maintain a suitable blood pressure or more likely in order to maintain a suitable concentration of sodium ions in the blood plasma. About 40 of the urea filtered is normally found in the final urine ref name boron791 , since there is more reabsorption than secretion along the nephron . It is regulated by antidiuretic hormone , which controls the amount reabsorbed in the collecting duct system and secreted into the loop of Henle . Overview table Class wikitable rowspan 2 Characteristic colspan 3 proximal tubule colspan 3 loop of Henle rowspan 2 Distal convoluted tubule colspan 4 Collecting duct system S1 S2 S3 Descending limb of loop of Henle descending limb thin ascending limb of loop of Henle thin ascending limb thick ascending limb of loop of Henle thick ascending limb connecting tubule initial collecting tubule cortical collecting ducts medullary collecting ducts reabsorption compared to filtered amount colspan 3 50 ref name boron791 cite book author Walter F., PhD. Boron title Medical Physiology A Cellular And Molecular Approaoch publisher Elsevier Saunders location year pages isbn 1 4160 2328 3 oclc doi Page 791 ref 70 secretion compared to filtered amount colspan 2 60 ref name boron791 reabsorption m Mole unit moles day Concentration Membrane potential electrical driving force m Volt V 3 ref name boron777 cite book author Walter F., PhD. Boron title Medical Physiology A Cellular And Molecular Approaoch publisher Elsevier Saunders location year pages isbn 1 4160 2328 3 oclc doi Page 777 ref 3 ref name boron ... more details
In Tooth dental anatomy , the lamina limitans is the innermost surface of the dentinal tubule that exist in dentin that lies in intimate contact with the long process of the odontoblast . It is hypocalcification hypocalcified and appears electron dense in electron microscope electron microscopy . It is composed of a fibrous outer layer and a membranous inner layer. It was previously known as the sheath of Neumann . ref name Salentijn Salentijn, L. Biology of Mineralized Tissues Mineralized Dental Tissues I Dentin & Cementum , Columbia University College of Dental Medicine post graduate dental lecture series, 2007 ref References Reflist Category Dental anatomy ... more details
tubule. The macula densa senses sodium chloride concentration in the distal tubule of the kidney ..., excessive filtration at the glomerulus or inadequate sodium uptake in the proximal tubule thick ascending loop of Henle brings fluid to the distal convoluted tubule that has an abnormally ... more details
. The distal convoluted tubule is labelled 2nd convoluted tubule the proximal convoluted tubule is the first in this illustration. The primary target of all thiazide diuretics, including metolazone, is the distal convoluted tubule , part of the nephron in the kidney , where they inhibit ... space, of the nephron tubule. Whatever remains in the tubule will travel to the urinary bladder bladder as urine and eventually be excreted. The cells lining the tubule modify the fluid inside, absorbing ... vessels. The other sides are tightly joined to neighboring cells. As with other regions, tubule cells in the distal convoluted tubule possess the adenosine triphosphate ATP powered sodium potassium ... two potassium ions in. The distal convoluted tubule cells also possess a sodium chloride symporter on the apical ... the tubule lumen as replacement. The symporter requires chloride to be transported in as well. Water ..., preventing sodium and chloride, and therefore water too, from leaving the lumen to enter the tubule ... the filtrate reaches the distal convoluted tubule, thiazide diuretics have limited effects on water ... tubule. Metolazone is frequently prescribed in addition to the loop diuretic. Metolazone may be used ... more details
Encyclopedia
top
