Which of the following structures is not part of the inner ear?

The pinna is the visible part of the ear that is located outside of the head, commonly referred to as the outer ear. Its primary function is to collect sound waves and direct them into the ear canal, ultimately facilitating the process of hearing. In contrast, the inner ear comprises structures such as the cochlea, utricle, and semicircular canals, which are responsible for the processing of sound and the maintenance of balance. The cochlea is essential for converting sound vibrations into neural signals, while the utricle and semicircular canals play critical roles in detecting head position and movement, contributing to the sense of balance. Understanding the anatomical divisions of the ear is crucial for distinguishing between these components and their associated functions.