The collecting duct is the last part where water and solutes can be resorbed and the final composition of urine is determined. The hormone aldosterone regulates the salt resorption; anti-diuretic hormone (ADH) controls the permeability for water.
Na+ ions are exchanged for other positive ions. Bicarbonate ions are exchanged for Cl- ions or H+ ions. The latter is important in balancing acid-base levels. The process of deamination reveals HCO3- and NH4+ions. Both ions serve in countertransports with other ions.
What is NOT true about regulation of water excretion?
Extra info: 65% of the filtered water is absorbed in the proximal tubule
The collecting duct is the site where the physiology is disrupted in a certain type of diabetes. Which one?
Extra info: In diabetes insipidus, there’s either a deficiency in ADH or there’s a deficient response to ADH. ADH is responsible for upregulating aquaporins in the collecting duct to reabsorb water. MODY is a hereditary type of diabetes mellitus.