Sodium and potassium setpoints

Sodium and potassium are loop quantities corrected by renal handling. Sodium loads are cleared via pressure natriuresis (a cited seam to the hemodynamic volume) and potassium via renal excretion; both return to their cited setpoints (Na ~140, K ~4.2 mM) in simulation.

Sodium and potassium setpoints are corrected by renal handling. Sodium couples to volume and pressure (a cited seam to the hemodynamic volume); potassium is set by renal excretion. Loads in either are corrected back to setpoint.

Renal correction of Na/K loads

A sodium load is returned to its setpoint (final 140.0 mM, cited ~140) and a potassium load to its setpoint (final 4.20 mM, cited ~4.2) by renal handling. The sodium↔volume↔pressure coupling that closes the sodium loop (pressure natriuresis) is owned by the hemodynamic volume and cited here, not re-emerged.