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Reabsorption and Secretion Along the Loop of Henle - Anatomy & Physiology (view source)
Revision as of 00:22, 15 January 2010
, 00:22, 15 January 2010→Vasa Recta Physiology
==Vasa Recta Physiology==
==Vasa Recta Physiology==
Water salts and urea can pass freely across the capillary walls of the vasa recta and therefore as the vessels reach deeper into the medulla where the interstitum surrounding them becomes more hypertonic the blood inside them in turn becomes more hypertonic. As the blood ascends back out of the medulla the osmolarity reduces until it is only slightly higher than when it entered. The conclusion drawn from this is that the solutes which are reabsorbed from the fluid mainly remain in the surrounding tissue and maintain the concentration gradient. If the system was not arranged in loops then this would not be possible. Although the blood leaving the medulla is always slighty more concentrated than when it entered upon reaching the cortex, if the urine being produced is very concentrated, it actually becomes hypo osmolar as more water than salt is being reabsorbed in the distal tubules which reside in there. Overall the osmolarity of the blood decreases when concentrated urine is being produced and increased when dilute urine is being produced.
Water, salts and urea can pass freely across the capillary walls of the vasa recta and therefore as the vessels reach deeper into the medulla where the interstitum surrounding them becomes more hypertonic, the blood inside them in turn becomes more hypertonic. As the blood ascends back out of the medulla, the osmolarity reduces until it is only slightly higher than when it entered. The conclusion drawn from this is that the solutes which are reabsorbed from the fluid mainly remain in the surrounding tissue and maintain the concentration gradient. If the system was not arranged in loops then this would not be possible. Although the blood leaving the medulla is always slighty more concentrated than when it entered upon reaching the cortex, if the urine being produced is very concentrated, it actually becomes hypo osmolar as more water than salt is being reabsorbed in the distal tubules which reside in there. Overall the osmolarity of the blood decreases when concentrated urine is being produced and increased when dilute urine is being produced.
The anatomy of the vasa recta can be found [[Microscopic Anatomy of the Nephron - Anatomy & Physiology#The Vasa Recta|here]]
The anatomy of the vasa recta can be found [[Microscopic Anatomy of the Nephron - Anatomy & Physiology#The Vasa Recta|here]]