function dv_dt = flowbind(t,v)

global Q
global Cmfa
global V
global kon
global koff
global Ptotal


Ncx = v(1);
Nmf = v(2);

Npunoc = Ptotal - Ncx;

flow_in = Q.*Cmfa;
flow_out = Q.*Nmf./V;
assoc_rate = kon.*Npunoc.*Nmf./V;
dissoc_rate = koff.*Ncx;


dv_dt = zeros(2,1);

dv_dt(1) = assoc_rate - dissoc_rate;
dv_dt(2) = dissoc_rate - assoc_rate + flow_in - flow_out;