The concentration of blood plasma is regulated by homeostatic mechanisms to maintain a constant water potential.
Complete the sentences below to describe how the body responds when a person is severely dehydrated.
Use the words in the list:
If a person is severely dehydrated, the water potential of the blood decreases.
This change is detected by specialised osmoreceptors in the ............................. .
These receptors stimulate the synthesis of the hormone ............................. .
This hormone is then transported along axons to the ............................. , where it is stored and subsequently released into the bloodstream.
Give one factor, other than low water intake, that could cause a person to produce a small volume of highly concentrated urine.
Proteinuria is a condition where proteins (such as albumin) pass through the filtration barrier in the kidneys and are excreted in the urine, which can indicate glomerular damage.
Describe a chemical test that could be used to determine if a patient's urine contains protein.
22 exam-style questions on OCR GCSE Biology 3.3 Maintaining internal environments, covering 3.3.1 Importance of a constant internal environment, 3.3.2 The skin and body temperature, 3.3.3 Insulin and blood sugar, 3.3.4 Glucagon and blood sugar, 3.3.5 Type 1 and type 2 diabetes, 3.3.6 Osmotic changes in body fluids, 3.3.7 Kidneys and water balance, 3.3.8 Structure of the kidney and tubule, 3.3.9 ADH and kidney tubule permeability, and 3.3.10 Responses to temperature and osmotic challenges. Each one has a worked solution and a mark scheme showing where the marks go.