What makes concentrated urine

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The part of your body getting scanned and the number of images needed play a role in determining how long the MRI will take. Here's what to expect. While bloodletting may sound like an ancient clinical treatment, it is still used in some — albeit rare and more medically sound — circumstances today. Health Conditions Discover Plan Connect. Urine Concentration Test. Medically reviewed by Debra Sullivan, Ph. What is the Purpose of a Urine Concentration Test?

How Is the Test Performed? Potential Side Effects of Taking the Test. Read this next. Urine Specific Gravity Test. Medically reviewed by Carissa Stephens, R. Urine Protein Test. Medically reviewed by Elaine K. Luo, M. Urine Hour Volume Test. Crawford , J. Doyle , and J. Service of urea in renal water conservation.

Del Greco , F. DE Wardener. DE Rouffignac , C. Micropuncture study of water, electrolytes, and urea movements along the loops of Henle in Psammomys.

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Fifth Bowditch lecture. Physiologist 4 1 : 35—55, Got r Schalk , C. Renal tubular functions: lessons from micropuncture. In: The Harvey Lectures. New York: Academic, , p. Evidence that the mammalian nephron functions as a countercurrent multiplier system. DC , Micropuncture study of the mammalian urinary concentrating mechanism: evidence for the countercurrent hypothesis. PubMed Google Scholar. Greger , R. Chloride reabsorption in the rabbit cortical thick ascending limb of the loop of Henle.

A sodium dependent process. Hargitay , B. Das Multiplikationsprinzip als Grundlage der Harnkonzentrierung in der Niere. Hilger , H. Klumper , and K. Wasserruckresorption und Ionentransport durch die Sammelrohzellen der Saugetiernier. Hiroka wA, W. Ueber den osmotischen Druck des Nierenparanchyms. Hofmeisters Beitr. Imai , M. Function of the thin ascending limb of Henle of rats and hamsters perfused in vitro.

Sodium chloride, urea, and water transport in the thin ascending limb of Henle: generation of osmotic gradients by passive diffusion of solutes. Jamison , R. Micropuncture study of segments of thin loop of Henle in the rat. Bennett , and R. Countercurrent multiplication by the thin loops of Henle. Buerkert , and F. A micropuncture study of collecting tubule function in rats with hereditary diabetes insipidus.

Jorgensen , B. The amphibian water economy with special regard to the effects of neurohypophyseal extracts. Acta Physiol. Kelman , R. Marsh , and H. Nonmonotonicity of solutions of linear differential equations occurring in the theory of urine formation. Koxxo, J. Sodium chloride and water transport in the descending limb of Henle. Rector , JR. Countercurrent multiplication system without active transport in inner medulla. Kidney Int. This process is vital," explains Prof.

For this reabsorption to work, the renal medulla that surrounds the collecting ducts must accumulate large quantities of salt and urea. Only then can water follow the osmotic gradient and be absorbed from the collecting duct into the renal medulla, where it eventually re-enters the circulation.

Christian Hinze of the MDC. This "switch" is the protein grainyhead-like 2, or GRHL2 - a transcription factor that can control the activity of genes. The molecule is produced in the collecting duct cells and enables these cells to form a tight barrier between the urine and the medulla. Experiments conducted in collecting duct cell cultures showed that GRHL2 has a significant impact on the permeability of the connection between cells.

Next, the scientists used an animal model to test whether these findings could be extrapolated to a living organism.