In clinical medicine, monitoring a patient's fluid balance is critical to prevent dehydration or fluid overload. A patient on an intensive care ward has their fluid intake and output monitored over a 24-hour period.
The table below shows the recorded volumes for each route of fluid gain and loss.
| Fluid Input Route | Volume (cm3\text{cm}^3cm3) | Fluid Output Route | Volume (cm3\text{cm}^3cm3) |
|---|---|---|---|
| Intravenous (IV) saline | 1850 | Urine | 1420 |
| Oral fluids (drinks) | 650 | Insensible loss (breathing & skin) | 950 |
| Metabolic water | 280 | Gastrointestinal loss | VVV |
During this 24-hour period, the patient's net fluid balance was positive, resulting in a net retention of 120 cm3 of water in their body.
Calculate the volume of water, VVV, lost via gastrointestinal loss.
62 exam-style questions on AQA GCSE Biology 5.3 Hormonal coordination in humans, covering 5.3.1 Human endocrine system, 5.3.2 Control of blood glucose concentration, 5.3.3 Maintaining water and nitrogen balance in the body, 5.3.4 Hormones in human reproduction, 5.3.5 Contraception, 5.3.6 The use of hormones to treat infertility (HT only), and 5.3.7 Negative feedback (HT only). Each one has a worked solution and a mark scheme showing where the marks go.