Perfecting an Appeal

A non-lawyer friend of mine asks me a question: “I was reading a Tenn. State Supreme Court decision on paternity fraud, linked to by Glenn Reynolds, and I came across this line: “Ms. Hodge perfected an appeal. Why ‘perfected’? It’s obviously a technical usage, and the meaning is clear enough in context, but what’s the reason for using that verb?”

I’ve heard the expression, myself, of course, but I’ve never thought to ask why that term. A casual search has not turned up any derivation of the word for me. Does anyone know why that verb is used?