There are 16-20 cartilagines tracheales. Cartilagines occupy 2/3 to 3/4 of the circumference of the trachea. (not 1/2) Anyway this is great thread. Good luck!
This is not a direct answer, but it should allow you to answer your own question: http://www.rsart.co.uk/2006/11/20/how-many-polygons-in-a-piece-of-string/
agree with the above, also for me the images in the sections(not main) are a bit too large, same goes for the header I think a 20% downscale would be ok.
Just finished the game, got 90% completing after 20 hours of gameplay. Solid 7/10 for gameplay, can't wait for the sequel that will improve on everything.