Why is the case that the below sentence has three verbs that weren't linked with any conjunction? Also, why use the comma prior to the last clause.

I don't know exactly why this sentence is structured as it is. I assume there were reduced parts or some parts of the clauses omitted.

A pupil of Freud (named) Wilhelm Reich (proposed) a theory (construed) out of the root of Freud's libido (,) of psychic energy he came to term orgone energy.