A research hospital's nephrologists are looking into the physiologic changes that occur in diabetes insipidus. The group creates a technique that allows tubular urine sampling in experimental animals with human-like physiology. Following hypophysectomy, tubular fluid samples are collected from multiple sites throughout the nephron. Fluid from which of the following sampling sites is most likely to have the highest osmolarity in the absence of antidiuretic hormone?

Question

Quizplus · Accepted Answer

Eductional Objective: Antidiuretic hormone (ADH) primarily affects the collecting ducts, increasing their water permeability. In the absence of ADH, the tubular fluid is most concentrated at the junction of the loop of Henle's descending and ascending limbs and most dilute in the collecting ducts.

A Research Hospital's Nephrologists Are Looking into the Physiologic Changes