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Slide 107-Human kidney: medulla |
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At high power, the simple cuboidal epithelial lining of the tubular collecting ducts and thick portions of the descending and ascending loops of Henle is evident. Note the erythrocyte-filled blood vessels of the vasa recta at upper left. These vessels, in conjunction with the loop of Henle, form the countercurrent system that maintains the high medullary osmolarity necessary for the production of concentrated urine. |