Control of blood water potentialAQA A-Level Biology: Flashcards

What these 13 flashcards ask

What is osmoregulation?
Where are the osmoreceptors that monitor blood water potential?
Where is ADH made, and where is it released?
Why is pressure high in the glomerulus?
Name the three layers filtrate crosses in ultrafiltration.
Which large molecules stay in the blood during ultrafiltration?
How is glucose reabsorbed in the PCT?
How are PCT cells adapted for reabsorption?
What does the ascending limb of the loop of Henle do?
What does the descending limb do?
Why do desert mammals have longer loops of Henle?
How does ADH affect the collecting duct?
What urine is produced when there is no ADH?

Exam questions on Control of blood water potential

A marathon runner sweats heavily during a race in hot weather and drinks nothing for two hours. Her blood water potential falls, and her body responds by changing the volume and concentration of her urine.
Explain how the release of ADH changes the volume and concentration of the runner's urine.2 marks
A physiologist is studying filtration in the kidney of a mammal. In each nephron, blood flows from an afferent arteriole into a knot of capillaries called the glomerulus, and leaves in an efferent arteriole. Fluid is forced out of the capillaries into the lumen of the Bowman's capsule.
Describe how glucose in the filtrate is reabsorbed into the blood in the proximal convoluted tubule.2 marks
The kangaroo rat lives in deserts and produces urine far more concentrated than that of a beaver, which lives by rivers. Anatomical studies show that the kangaroo rat has nephrons with much longer loops of Henle than the beaver, which has nephrons with short loops.
Describe how the loop of Henle maintains a gradient of sodium ions in the tissue fluid of the medulla.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).