A person produces a large volume of dilute urine even though the ADH concentration in their blood is high. Giving additional ADH does not reduce their urine volume.
Which explanation is most consistent with these results?
the pituitary releases too much ADH, so much extra water is reabsorbed
the collecting ducts respond strongly to ADH, so little extra water is reabsorbed
the pituitary releases too little ADH, so much extra water is reabsorbed
the collecting ducts respond poorly to ADH, so little extra water is reabsorbed
45 exam-style questions on Edexcel GCSE Biology 7.4 Blood glucose and the urinary system, covering 7.4.1 Insulin and blood glucose control, 7.4.2 Glucagon and blood glucose regulation, 7.4.3 Type 1 and type 2 diabetes, 7.4.4 Structure of the urinary system, 7.4.5 Structure and function of the nephron, 7.4.6 ADH and water regulation, 7.4.7 Treatments for kidney failure, and 7.4.8 Production of urea in the liver. Each one has a worked solution and a mark scheme showing where the marks go.