Which component is NOT part of the Cessna 172's structure for managing flight controls?

The hydraulic system is not part of the Cessna 172's structure for managing flight controls because this aircraft primarily uses a mechanical control system. The Cessna 172 is designed with traditional flight control surfaces, including ailerons, elevators, and a rudder, all controlled through a system of cables and pulleys that mechanically link the pilot's inputs to the control surfaces.

In contrast, a hydraulic system would involve fluid pressures to operate flight controls, which is more common in larger, more complex aircraft. In the Cessna 172, the simplicity and reliability of a mechanical system are favored, emphasizing ease of maintenance and straightforward operation for general aviation pilots.