Negative feedback
Blood glucose
The nephron
Loop of Henle
ADH & water
Practice
gain — how hard the effector corrects
1.5 per min
delay — detection to correction
0.8 min
+1 °C — exercise, a hot day
−1 °C — a cold plunge
positive feedback — the effector amplifies the change instead of reversing it
Healthy
Type 1 diabetes — no insulin
Type 2 diabetes — insulin resistance
Eat a meal (+3)
Exercise (−1.5)
Stress — adrenaline (+1)
Insulin injection
blood glucose — the renal threshold is about 10 mmol dm
−3
5.0 mmol dm⁻³
Beaver — a short loop
Human
Desert rodent — a long loop
loop length, relative to a human nephron
1.00×
Dehydrated
Balanced
Drinking a lot
water balance — dehydrated on the left, over-hydrated on the right
balanced
alcohol or caffeine — ADH release suppressed
negative feedback — a graph against time
1
—
Check
Hint
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How to think about it
Common mistakes