in·trin·sic 
(ĭn-trĭnzĭk, -sĭk)
(ĭn-trĭnzĭk, -sĭk)adj.
1. Of or relating to the essential nature of a thing; inherent.
2. Anatomy Situated within or belonging solely to the organ or body part on which it acts. Used of certain nerves and muscles.
[Middle English intrinsique, inner, from Old French intrinseque, from Late Latin intrīnsecus, inward, from Latin, inwardly; see en in the Appendix of Indo-European roots.]
in·trinsi·cal·ly adv.