intrinsic
Of or relating to the essential nature of a thing; inherent.
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.]
Situated entirely within, or pertaining exclusively to, a part.
inner
1. being or located further inside an inner room
2. happening or occurring inside inner movement
3. relating to the soul, mind, spirit, etc. inner feelings
4. more profound or obscure; less apparent the inner meaning
5. exclusive or private inner regions of the party
6. (Chemistry) Chem (of a compound) having a cyclic structure formed or apparently formed by reaction of one functional group in a molecule with another group in the same molecule an inner ester