A medicine acts on the pituitary gland for several hours.
A healthy adult takes this medicine. The adult consumes the same volume of water and the same mass of food during each four-hour period.
| Measurement | Before taking the medicine | While the medicine is acting |
|---|---|---|
| ADH concentration in the blood in pg cm−3\mathrm{pg\,cm^{-3}}pgcm−3 | 3.8 | 0.8 |
| volume of urine produced in cm3\mathrm{cm^3}cm3 | 260 | 780 |
| concentration of dissolved substances in the urine in g dm−3\mathrm{g\,dm^{-3}}gdm−3 | 45 | 15 |
Explain the results and predict how the ADH concentration and the urine will change when the medicine has worn off, before the adult drinks any more water.
94 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.