This is an idealized depiction of a cross section through the flagellum (looking from posterior to anterior).

The flagellar axoneme (1) is composed of the standard 9 +2 doublets of microtubules. The axoneme is attached to zone 1 of the paraflagellar rod (PFR) (2) primarily by cross links with axoneme doublet number 7 (3). The flagellum is attached to the cell body via uncharacterized structure (4) that link the PFR and the flagellum attachment zone (FAZ) filament (5). The paraflagellar rod attaches to both the axoneme and the FAZ filament by uncharacterized cross links, and the paraflagellar rod is composed of three matrix like parts.   The FAZ filament (6) resides on the cytoplasmic side of the plasma membrane and is attached to the plasma membrane via an uncharacterized attachment complex. It is the physical properties of the axoneme, PFR, and FAZ that convert the flagellar beat to cellular movement.

 Immediately adjacent to the FAZ filament is a specialized reticulum associated quartet of microtubules (7). The exact function of these four specialized microtubules or associated reticulum is currently unknown. Nonetheless, these structures co-purify with the flagellar fraction of the cytoskeleton (Calcium insoluble fraction).