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Encyclopedia > Cortical collecting duct

The collecting duct system of the kidney consists of a series of tubules and ducts that connect the nephrons to the ureter. It participates in electrolyte and fluid balance through reabsorption and excretion, processes regulated by the hormones aldosterone and antidiuretic hormone. Human kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... Nephron of the kidney A nephron is the basic structural and functional unit of the kidney. ... Transverse section of ureter. ... An electrolyte is a substance that dissociates into free ions when dissolved (or molten), to produce an electrically conductive medium. ... A hormone (from Greek horman - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... Aldosterone is a steroid hormone synthesized from cholesterol by the enzyme aldosterone synthase. ... Antidiuretic hormone (ADH), or arginine vasopressin (AVP), is a peptide hormone produced by the hypothalamus, and stored in the posterior part of the pituitary gland. ...


Anatomically, there are several components of the collecting duct system, including the connecting tubules, cortical collecting ducts, and medullary collecting ducts.

Contents


Function

The collecting duct system is the last component of the kidney to influence the body's electrolyte and fluid balance. In humans, the system accounts for 4-5% of the kidney's reabsorption of sodium and 5% of the kidney's reabsorption of water. At times of extreme dehydration, over 24% of the filtered water may be reabsorbed in the collecting duct system. An electrolyte is a substance that dissociates into free ions when dissolved (or molten), to produce an electrically conductive medium. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ...


The wide variation in water reabsorption levels for the collecting duct system reflects its dependence on hormonal activation. The collecting ducts, particularly the outer medullary and cortical collecting ducts, are largely impermeable to water without the presence of antidiuretic hormone (ADH, or vasopressin). In the absence of ADH, water in the renal filtrate is left alone to enter the urine, promoting diuresis. When ADH is present, water channels allow for the reabsorption of this water, thereby inhibiting diuresis. Antidiuretic hormone (ADH), or arginine vasopressin (AVP), is a peptide hormone produced by the hypothalamus, and stored in the posterior part of the pituitary gland. ... Diuresis is the production of urine by the kidney. ... A water channel is an experimental tank for studying resistance and propulsion behaviour of ships, submarines, or other sea vessels. ...


The collecting duct system participates in the regulation of other electrolytes, including chloride, potassium, hydrogen ions, and bicarbonate. The chloride ion is formed when the element chlorine picks up one electron to form the anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and are also called chlorides. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Atomic mass 39. ... Hydronium is the common name for the cation H3O+. Nomenclature According to IUPAC ion nomenclature, it should be referred to as oxonium. ... This refers to the bicarbonate ion, for baking soda, see Sodium bicarbonate. ...


Anatomy

Connecting tubules

Main article: Connecting tubule

With respect to the renal corpuscle, the connecting tubule is the most proximal part of the collecting duct system. It is adjacent to the distal convoluted tubule, the most distal segment of the renal tubule. Connecting tubules from several adjacent nephrons merge to form cortical collecting tubules, and these may join to form cortical collecting ducts. A renal corpuscle is the initial filtering component of a nephron in the kidney. ... Kidney nephron The distal convoluted tubule (DCT) is a portion of kidney nephron between the loop of Henle and the collecting duct system. ... Nephron of the kidney A nephron is the basic structural and functional unit of the kidney. ...


Connecting tubules of some juxtamedullary nephrons may arch upward, forming an arcade.


Cortical collecting ducts

The cortical collecting ducts receive filtrate from multiple connecting tubules and descend into the renal medulla to form medullary collecting ducts. The renal medulla is the innermost part of the kidney. ...


Medullary collecting ducts

Medullary collecting ducts are divided into outer and inner segments, the latter reaching more deeply into the medulla. The terminal portions of these ducts are the papillary ducts, which end at the renal papilla and empty into a minor calyx.


The variable reabsorption of water and, depending on fluid balances and hormonal influences, the reabsorption or secretion of sodium, potassium, hydrogen and bicarbinate ion continues here.


Cell types

Each component of the collecting duct system contains two cell types, intercalated cells and a segment-specific cell type. For the connecting tubules, this specific cell type is the connecting tubule cell; for the collecting ducts, it is the principal cell. The inner medullary collecting ducts contain an additional cell type, called the inner medullary collecting duct cell.


References

  • Eaton, Douglas C., Pooler, John P. (2004). Vander's Renal Physiology, 6, Lange Medical Books/McGraw-Hill. ISBN 0-07-135728-9.
Urinary system - Kidney - edit
Renal capsule | Renal cortex | Renal medulla (Renal sinusRenal pyramids) | Renal calyx | Renal pelvis
Nephron - Renal corpuscle (GlomerulusBowman's capsule) → Proximal convoluted tubule → Loop of Henle → Distal convoluted tubule → Collecting ducts

Juxtaglomerular apparatus (Macula densaJuxtaglomerular cells) The urinary system is the organ system that produces, stores, and carries urine. ... Human kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... The renal capsule is a tough fibrous layer surrounding the kidney and covered in a thick layer of perinephric adipose tissue. ... The renal cortex is the outer portion of the kidney between the renal capsule and the renal medulla. ... The renal medulla is the innermost part of the kidney. ... The renal sinus is a cavity within the kidney which is occupied by the renal pelvis, renal calices, blood vessels, nerves and fat. ... Renal pyramids are cone-shaped tissues of the kidney. ... A calyx is a part in the kidney. ... The renal pelvis represents the dilated proximal part of the ureter. ... Nephron of the kidney A nephron is the basic structural and functional unit of the kidney. ... A renal corpuscle is the initial filtering component of a nephron in the kidney. ... The glomerulus is a capillary bed found surrounded by the Bowmans capsule of the nephron in the vertebrate kidney. ... Bowmans capsule is a blind sac at the beginning of the tubular component of a nephron in the mammalian kidney. ... The loop of Henle is a section of the nephron that leads from the proximal convoluted tubule to the distal convoluted tubule in the kidney. ... Kidney nephron The distal convoluted tubule (DCT) is a portion of kidney nephron between the loop of Henle and the collecting duct system. ... The juxtaglomerular apparatus is a renal structure consisting of the macula densa and juxtaglomerular cells. ... In the kidney, the macula densa is an area of closely packed specialised cells lining the thick ascending limb of the Loop of Henle where it lies next to the glomerular vascular pole. ... The juxtaglomerular cells are specialized cells that stimulate the secretion of the adrenal hormone aldosterone and play a major role in renal autoregulation, the kidneys self-governance. ...


Renal circulation - Renal artery → Interlobar artery → Arcuate arterioles → Afferent arterioles → Glomerulus → Efferent arterioles → Vasa recta → Arcuate vein → Renal vein Grays Fig. ... Human kidneys viewed from behind with spine removed The renal arteries normally arise off the abdominal aorta and supply the kidneys with blood. ... The afferent arterioles are a group of blood vessels that supply the nephrons in many excretory systems. ... The glomerulus is a capillary bed found surrounded by the Bowmans capsule of the nephron in the vertebrate kidney. ... The Efferent arterioles are a group of blood vessels that are part of the urinary system of many animals. ... A nephron, the vasa recta is labelled arteria recta The vasa recta is a loop of the renal circulation that surrounds the Loop of Henle, part of the nephron in the medulla of the kidney. ... Kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ...

Renal physiology
Filtration - Ultrafiltration | Countercurrent exchange

Hormones effecting filtration - Antidiuretic hormone (ADH) | Aldosterone | Atrial natriuretic peptide Renal physiology is the study of the physiology of the kidneys. ... The article is about the separation process. ... Ultrafiltration (UF) is a pressure-driven membrane process for purifying and concentrating macromolecular (10^3 - 10^6 Da) solutions, especially protein solutions. ... Countercurrent exchange is a mechanism used to transfer some component of a fluid from one flowing current of fluid to another across a permeable barrier between them. ... Antidiuretic hormone (ADH), or arginine vasopressin (AVP), is a peptide hormone produced by the hypothalamus, and stored in the posterior part of the pituitary gland. ... Aldosterone is a steroid hormone synthesized from cholesterol by the enzyme aldosterone synthase. ... Atrial natriuretic factor (ANF), atrial natriuretic peptide (ANP) or atriopeptin, is a peptide hormone involved in the homeostatic control of body water and sodium. ...


Endocrine - Renin | Erythropoietin (EPO) | Calcitriol (Active vitamin D) | Prostaglandins The endocrine system is a control system of ductless endocrine glands that secrete chemical messengers called hormones that circulate within the body via the bloodstream to affect distant organs. ... Renin, also known as angiotensinogenase, is a circulating enzyme (EC 3. ... Erythropoietin Erythropoietin (or EPO) is a glycoprotein hormone that is a growth factor for erythrocyte (red blood cell) precursors in the bone marrow. ... Vitamin D is a fat soluble vitamin that contributes to the maintenance of normal levels of calcium and phosphorus in the bloodstream. ... A prostaglandin is any member of a group of lipid compounds that are derived from fatty acids and have important functions in the animal body. ...

Assessing Renal function / Measures of Dialysis
Glomerular filtration rate | Creatinine clearance | Renal clearance ratio | Urea reduction ratio | Kt/V | Standardized Kt/V | Hemodialysis product

  Results from FactBites:
 
Rat Renal Arcade Segment Expresses Vasopressin-regulated Water Channel and Vasopressin V2 Receptor -- Kishore et al. ... (6206 words)
of superficial nephrons to the cortical collecting ducts.
Woodhall, P.B., and C.C. Tisher (1973) Response of the distal tubule and cortical collecting duct to vasopressin in the rat.
Morphology of the loop of Henle, distal tubule, and collecting duct.
Collecting duct system at AllExperts (617 words)
The collecting duct system of the kidney consists of a series of tubules and ducts that connect the nephrons to the ureter.
The collecting duct system is the last component of the kidney to influence the body's electrolyte and fluid balance.
The collecting ducts, particularly the outer medullary and cortical collecting ducts, are largely impermeable to water without the presence of antidiuretic hormone (ADH, or vasopressin).
  More results at FactBites »

 
 

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