how to solve equation which is time derivative with space variation in matlab?

i want to solve equation as below :

Cc, Cd- variable varies with time and z direction.

a1 a2 a3 are parameter which can be found out from Cc(z)

dCc(z)/dt = a1*(Cc(z-1) - Cc(z))/dz + a2 + a3;

b1 b2 b3 are parameter which can be found out from Cd(z)

dCd(z)/dt = b1*(Cd(z-1) - Cd(z))/dz + b2 + b3;

how to solve it simultaneously?