Final answer:
The vestibular system, specifically the semicircular canals, utricle, and saccule within the inner ear, controls balance and equilibrium, sending signals to the cerebellum and brainstem to maintain postural stability.
Step-by-step explanation:
The Structure Controlling Balance and Equilibrium
The structure that controls balance and equilibrium is part of the vestibular system, which includes components such as the utricle, saccule, and the semicircular canals. Information about head movement and position is encoded by the vestibule of the inner ear and processed by the brain to maintain balance. The nerves composed of axons from the vestibular ganglion transmit signals to both the vestibular nuclei of the medulla and directly to the cerebellum, facilitating coordination of head and neck movements as well as eye movements to maintain visual attention. These signals allow the peripheral nervous system to trigger skeletal muscle contractions necessary for balance.
It's important to note that the ossicles, which include the malleus, incus, and stapes, are tiny bones found in the middle ear that are responsible for transmitting sound vibrations from the eardrum to the inner ear; however, they are not specifically responsible for balance and equilibrium. That function is attributed to the previously mentioned parts of the vestibular system.