Is it farther or further?
late 15c., "interior, inward, internal," from Middle French intrinsèque "inner" (13c.), from Medieval Latin intrinsecus "interior, internal," from Latin intrinsecus (adv.) "inwardly, on the inside," from intra "within" (see intra-) + secus "alongside," originally "following" (related to sequi "to follow;" see sequel). Meaning "belonging to the nature of a thing" is from 1640s. Related: Intrinsicly.
intrinsic in·trin·sic (ĭn-trĭn'zĭk, -sĭk)
Of or relating to the essential nature of a thing.
Situated within or belonging solely to the organ or body part on which it acts. Used of certain nerves and muscles.