Search results
Results from the WOW.Com Content Network
Whereas the peritubular capillaries surround the cortical parts of the tubules, the vasa recta go into the medulla and are closer to the loop of Henle, [1] [2] and leave to ascend to the cortex. [3] [4] Terminations of the vasa recta form the straight venules, branches from the plexuses at the apices of the medullary pyramids.
Peritubular capillaries surround the cortical parts of the proximal and distal tubules, while the vasa recta go into the medulla to approach the loop of Henle. [1] [2] About one-fifth of the blood plasma is filtered into Bowman's capsule as the blood passes through the glomerular capillaries; four-fifths continues into the peritubular capillaries.
These capillaries (called the vasa recta; recta is from the Latin for "straight") also have a countercurrent multiplier mechanism that prevents washout of solutes from the medulla, thereby maintaining the medullary concentration. As water is osmotically driven from the descending limb into the interstitium, it readily enters the capillaries ...
Note 3: The efferent arterioles do not directly drain into the interlobular vein, but rather they go to the peritubular capillaries first. The efferent arterioles of the juxtamedullary nephron drain into the vasa recta.
The blood exiting the efferent arterioles of these nephrons enter the vasa recta, which are straight capillary branches that deliver blood to the renal medulla. These vasa recta run adjacent to the descending and ascending loop of Henle and participate in the maintenance of the medullary countercurrent exchange system.
The descending vasa recta, ascending vasa recta vessels, and the loop of Henle together form the countercurrent system of the kidney. In the afferent arteriole, blood is supplied at high pressure, which promotes filtration, and in the efferent arteriole, it is at low pressure, which promotes reabsorption .
These structures include the vasa rectae (both spuria and vera), the venulae rectae, the medullary capillary plexus, the loop of Henle, and the collecting tubule. [1] The renal medulla is hypertonic to the filtrate in the nephron and aids in the reabsorption of water. Blood is filtered in the glomerulus by solute size.
The vasa recta have a similar loop shape so that the gradient does not dissipate into the plasma. [citation needed] The mechanism of counter current multiplication works together with the vasa recta's counter current exchange to prevent the wash out of salts and maintain a high osmolarity at the inner medulla. [citation needed]