<prompt> Aldosterone acts at:Collecting ductGlomerulusProximal convoluted tubuleLoop of Henle  <response>: Ans. A Collecting ductRef: Ganong, 23rd ed. pg. 648 Aldosterone is secreted from adrenal cortex. Action of aldosterone is localized to distal tubule are collecting duct. Mechanism: Stimulates NaK ATPase at basolateral end which generate gradient for movement of sodium ion from apical membrane causing an increase in sodium: reabsorption. 