What anatomical structure has an outer third that is cartilaginous and the inner two-thirds that are bony?

The ear canal, also known as the external auditory canal, is characterized by its unique anatomical structure where the outer third is composed of cartilage, while the inner two-thirds consists of bone. This design serves multiple purposes, including maintaining the canal's shape and protecting the sensitive inner structures of the ear.

The cartilaginous outer third provides flexibility and cushioning, which helps prevent injury from external forces. In contrast, the bony inner two-thirds provides durability and stability, vital for directing sound waves toward the tympanic membrane (eardrum). This combination of materials is essential for the proper function of the ear canal, making it a crucial part of the auditory system.

Understanding the structure of the ear canal is important for audiologists as it helps in diagnosing and treating various ear conditions, as well as in the fitting and application of hearing aids. This knowledge also guides professionals in managing ear health, preventing infections and accommodating various procedures related to audiology.