Inside our bodies... well, male ones, anyway

[16:24] Your Testis Guide whispers: You will probably want to switch to Mouselook (esc esc m). Your mouse now controls your camera (view).
[16:24] Your Testis Guide whispers: We are now inside a tubule. We will be moving left and down.
[16:24] Your Testis Guide whispers: Surrounding you are the tails of sperm attatched to the cells lining the tubule.
[16:25] Your Testis Guide whispers: Flying by your head are mature sperm that are travelling down the tubule towards the collecting ducts.
[16:25] Your Testis Guide whispers: This corridor will take us to a higher magnification of the tubule.
[16:25] Your Testis Guide whispers: This is the entrance to a single seminiferous tubule.