  We discuss the solvability of a fairly general class of systems of perturbed
Hammerstein integral equations with functional terms that depend on several
parameters. The nonlinearities and the functionals are allowed to depend on the
components of the system and their derivatives. The results are applicable to
systems of nonlocal second order ordinary differential equations subject to
functional boundary conditions, this is illustrated in an example. Our approach
is based on the classical fixed point index.
