This transmission electron micrograph (TEM) of Trypanosoma brucei brucei shows a transverse section through a bloodstream form of the parasite. It is the parasite that causes sleeping sickness. The flagellum is clearly visible as a discrete structure on the right, with a 9 + 2 microtubule axoneme running through the center and a strengthening paraflagellar rod underneath. Other visible structures include the glycoprotein coat and a row of subpellicular microtubules just beneath the cell surface.