Straight arterioles of kidney
A nephron, the vasa recta are labeled arteriolae rectae
|Source||Arcuate arteries of the kidney, efferent arteriole|
|Branches||Straight venules of kidney, arcuate vein|
|Latin||arteriolae rectae renis|
|Vasa recta renis|
- For the intestinal structure, see Vasa recta (intestines)
In the blood supply of the kidney, the straight arterioles of kidney (or vasa recta renis) are a series of straight capillaries in the medulla (Latin: vasa, "vessels"; recta, "straight"). They lie parallel to the loop of Henle.
These vessels branch off the efferent arterioles of juxtamedullary nephrons (those nephrons closest to the medulla), enter the medulla, and surround the loop of Henle. The straight arterioles are peritubular capillaries, specifically those that surround the loop of Henle.
Each straight arteriole has a hairpin turn in the medulla and carries blood at a very slow rate, two factors crucial in the maintenance of countercurrent exchange that prevent washout of the concentration gradients established in the renal medulla.
The maintenance of this concentration gradient is one of the components responsible for the kidney's ability to produce concentrated urine.
On the descending portion of the straight arterioles, NaCl and urea are reabsorbed into the blood, while water is secreted. On the ascending portion, NaCl and urea are secreted into the interstitium, while water is reabsorbed.
However, other sources consider "vasa recta renis" to refer to both the arterial and venous portions.
The "renis" is often omitted, but there do exist two other structures with the same name:
- vasa recta (intestines) (in the ileum and jejunum)
- the straight portion of the seminiferous tubule, though this is usually called the tubuli recti.
The slow blood flow in the straight arterioles makes them a likely location of thrombosis in hypercoagulable states, or tissue loss due to erythrocyte sickling in sickle cell disease. Ischemia that results may lead to renal papillary necrosis.
- http://faculty.stcc.edu/AandP/AP/AP2pages/Units24to26/urinary/nephron.htm. Missing or empty
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- Physiology: 7/7ch08/7ch08p07 - Essentials of Human Physiology
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- jejunumileum at The Anatomy Lesson by Wesley Norman (Georgetown University)
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