Difference between revisions of "Reabsorption and Secretion Along the Distal Tubule and Collecting Duct - Anatomy & Physiology"
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− | {{ | + | {{toplink |
− | + | |backcolour = C1F0F6 | |
+ | |linkpage =Reabsorption and Secretion Along the Nephron - Anatomy & Physiology | ||
+ | |linktext =REABSORPTION AND SECRETION ALONG THE NEPHRON | ||
+ | |maplink = Urinary System (Content Map) - Anatomy & Physiology | ||
+ | |pagetype =Anatomy | ||
+ | }} | ||
+ | <br> | ||
+ | |||
==Distal Tubule== | ==Distal Tubule== | ||
− | [[Image: | + | [[Image:disttubexch.jpg|right|thumb|300px|<small><center>Exchange in the Principal Cells of the Distal Tubule</center></small>]] |
* Important site of regulation of ions and water | * Important site of regulation of ions and water | ||
* Less emphasis on bulk transport compared with proximal tubule | * Less emphasis on bulk transport compared with proximal tubule | ||
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* It is able to do this as it has high resistance epithelia. Allowing it to maintain substantial gradients across it | * It is able to do this as it has high resistance epithelia. Allowing it to maintain substantial gradients across it | ||
* Very important for the homeostasis of: | * Very important for the homeostasis of: | ||
− | ** Sodium | + | ** [[Sodium Homeostasis - Physiology#Distal Tubule and Collecting Ducts| Sodium]] |
− | ** Potassium | + | ** [[Potassium Homeostasis - Physiology#Distal Tubule| Potassium]] |
− | ** Acid | + | ** [[Acid Base Balance By The Kidney - Anatomy & Physiology#Secretion of H+ in the Distal Tubule and Collecting Ducts| Acid Base]] |
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* There are two cell types present each with different functions. They are similar to the cells of the collecting ducts | * There are two cell types present each with different functions. They are similar to the cells of the collecting ducts | ||
** Principal cells | ** Principal cells | ||
*** Absorb sodium | *** Absorb sodium | ||
*** Excrete potassium and hydrogen | *** Excrete potassium and hydrogen | ||
− | *** Site of action of [[ | + | *** Site of action of [[Aldosterone]] |
** Intercalated cells | ** Intercalated cells | ||
*** ATP driven proton secretion | *** ATP driven proton secretion | ||
− | + | ==Juxtaglomerular Apparatus== | |
+ | [[Image:juxtaapp.jpg|right|thumb|200px|<small><center>Histology section showing the juxtaglomerular apparatus (© RVC 2008)</center></small>]] | ||
* The terminal portion of the straight distal tubule contacts the afferent and efferent vessels supplying its own glomerulus | * The terminal portion of the straight distal tubule contacts the afferent and efferent vessels supplying its own glomerulus | ||
* These vessels are said to embrace the distal tubule | * These vessels are said to embrace the distal tubule | ||
* Here a special apparatus called the Juxtaglomerular Apparatus has 3 different structures: | * Here a special apparatus called the Juxtaglomerular Apparatus has 3 different structures: | ||
− | ** The tubular epithelial cells of the distal tubule which are in contact with the arterioles supplying the glomerulus of that nephron are called the '''macula densa'''. They play a vital role in the [[ | + | ** The tubular epithelial cells of the distal tubule which are in contact with the arterioles supplying the glomerulus of that nephron are called the '''macula densa'''. They play a vital role in the [[Autoregulation of GFR - Anatomy and Physiology#Tubuloglomerular Feedback (TGF)|regulation of the GFR]]. |
− | ** The Juxtaglomerular Cells are smooth muscle cells which adjoin the macula densa in the capillary wall. | + | ** The [[Juxtaglomerular Cells of The Distal Tubule - Renal Physiology | Juxtaglomerular Cells]] are smooth muscle cells which adjoin the macula densa in the capillary wall. |
** The Extraglomerular Mesangium has an unclear function | ** The Extraglomerular Mesangium has an unclear function | ||
− | ==== | + | ==Developmental== |
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Develops from metanephric tubule | Develops from metanephric tubule | ||
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Revision as of 15:07, 3 September 2008
|
Distal Tubule
- Important site of regulation of ions and water
- Less emphasis on bulk transport compared with proximal tubule
- More emphasis on fine management
- It is able to do this as it has high resistance epithelia. Allowing it to maintain substantial gradients across it
- Very important for the homeostasis of:
- There are two cell types present each with different functions. They are similar to the cells of the collecting ducts
- Principal cells
- Absorb sodium
- Excrete potassium and hydrogen
- Site of action of Aldosterone
- Intercalated cells
- ATP driven proton secretion
- Principal cells
Juxtaglomerular Apparatus
- The terminal portion of the straight distal tubule contacts the afferent and efferent vessels supplying its own glomerulus
- These vessels are said to embrace the distal tubule
- Here a special apparatus called the Juxtaglomerular Apparatus has 3 different structures:
- The tubular epithelial cells of the distal tubule which are in contact with the arterioles supplying the glomerulus of that nephron are called the macula densa. They play a vital role in the regulation of the GFR.
- The Juxtaglomerular Cells are smooth muscle cells which adjoin the macula densa in the capillary wall.
- The Extraglomerular Mesangium has an unclear function
Developmental
Develops from metanephric tubule