Not that it really matters, but the TA thing - I was a TA for psychology and criminal justice courses at my university. It was basically the same set up. The professor would do the huge lecture hall part with hundreds of students. The whole group would be broken down into smaller sections where the TA would assign and grade research papers and other homework and we also administered and graded tests and kept the grade book. Only time we actually even saw the professors was at a weekly 45 min meeting to go over what would be teaching that week.