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The diagram shows the body's response to dehydration - Edexcel - GCSE Biology - Question 5 - 2014 - Paper 1
Question 5
The diagram shows the body's response to dehydration. dehydration brain thirst hormone response kidney (a) Use the diagram to help explain the body's hormonal ... show full transcript
Worked Solution & Example Answer:The diagram shows the body's response to dehydration - Edexcel - GCSE Biology - Question 5 - 2014 - Paper 1
Step 1
Use the diagram to help explain the body's hormonal response to dehydration.
Answer
When the body experiences dehydration, the hypothalamus in the brain detects the increase in blood osmolarity due to the lack of water.
This triggers the sensation of thirst, prompting an individual to drink fluids.
Additionally, the brain initiates a hormonal response by signaling the pituitary gland to release antidiuretic hormone (ADH), also known as vasopressin.
ADH travels through the bloodstream to the kidneys, where it increases the permeability of the kidney tubules, allowing more water to be reabsorbed back into the bloodstream. This reduces urine output and helps restore the body's fluid balance.