How does the composition of the fi ltrate change as it travels through the loop of Henle? A. In the ascending limb, the volume decreases and in the descending limb, the concentration increases. B. In the descending limb, the volume decreases and in the ascending limb, the concentration decreases. C. In the descending limb, the volume decreases and in the ascending limb, the concentration increases. D. In the ascending limb, the volume decreases and in the descending limb, the concentration decreases.
Option B. The descending limb is permeable to water so water fl ows out of the tubule reducing fi ltrate extent. The ascending limb is impermeable to water, so its extent does now no longer change, but sodium, potassium and chloride ions are reabsorbed which decreases the concentration of the filterate.
