💡 Isovolumetric contraction = Highest O2 consumption. a wave = atrial contraction.

💡 Inulin = GFR. PAH = Renal Plasma Flow.

💡 Phase 0 (Heart) = Na+ influx. Phase 2 = Ca2+ plateau.

💡 Cortisol = highest in morning. PTH increases Ca2+, lowers PO4.