Posted this in the Female Section but they seem to be rather quiet (or just ignorant

) about it. Thought some of you guys might be able to help.
Ok, here's my question. When I train arms I use a variety of exercises, grips etc. to make sure I hit each different head of the biceps & triceps.
The problem is I'm not EXACTLY sure which grips hit which parts of the bi/tri which makes it a bit difficult to put my mind in the particular PART of the muscle.
(When i do calf raises, for example, I know that pointing the toes in hits the outer head a bit more while turning them out hits the inner.)
What I'd like to know is what grips put the emphasis in which parts of the arm muscles..............
for example:
press downs done with an overhand grip hits which head of the tri?
press downs done with a reverse grip? (Is it the lower?)
and rope press downs with palms facing in?
BB curls with overand & reverse grip?
As far as I know Hammer curls (palms facing in) hit the peak. Correct?
I know I'm nit-picking here but just want to be sure as I believe the direction of the thumbs/grip does have an impact on WHERE the bicep/tricep is being hit to a greater or lesser degree.
Hope this question makes sense. If anyone knows of a good site for a breakdown of this it would be hugely appreciated.