A 34-year-old missionary in southern Asia is traveling to a remote village and becomes stranded when his bus breaks down. He has no access to water for 36 hours, during which his urine osmolality reaches 1100 mOsm/L. Urine concentration depends primarily on the serum level of vasopressin, which is regulated by the neurohypophysis in response to plasma osmolality and blood volume. Which of the following nephron segments responds to vasopressin by increasing absorption of a specific solute that is important for generating a high medullary concentration gradient?

Question

A 34-year-old missionary in southern Asia is traveling to a remote village and becomes stranded when his bus breaks down.  He has no access to water for 36 hours, during which his urine osmolality reaches 1100 mOsm/L.  Urine concentration depends primarily on the serum level of vasopressin, which is regulated by the neurohypophysis in response to plasma osmolality and blood volume.  Which of the following nephron segments responds to vasopressin by increasing absorption of a specific solute that is important for generating a high medullary concentration gradient?

Quizplus · Accepted Answer

Eductional Objective: Antidiuretic hormone acts on the medullary segment of the collecting duct to increase urea and water reabsorption, allowing for the production of maximally concentrated urine.

A 34-Year-Old Missionary in Southern Asia Is Traveling to a Remote