Stretching of the atrial muscle cells releases a hormone called atrial natriuretic factor (ANF). ANF relaxes the juxtaglomerular (JG) cells of the afferent arteriole and thereby increases GFR and urine output.
Predator and Prey relationships would have the most effect on an ecosystem's stability because they keep a limit number on the opposing population (ex. rabbit population can only get so high because wolves keep eating them / wolf population can only be so high because there is't enough rabbit to eat)
A. sees more detail. It zooms in enough to see the electrons hence the name