Are there prefixes which have the meaning 'originating from within', or 'originating from outside'?
Solution 1:
extra-
prefix: extra-
outside; beyond.
"extracellular"
beyond the scope of.
"extracurricular"
intra-
prefix
(added to adjectives) on the inside; within.
"intramural"
Solution 2:
ex- out of, from, away from.
http://www.medilexicon.com/medicaldictionary.php?t=30824
Example: excementosis
Reference for existing use in med-term:
http://medical-dictionary.thefreedictionary.com/excementosis