What separates the external ear from the middle ear?

The structure that separates the external ear from the middle ear is the tympanic membrane, commonly known as the eardrum. This thin, cone-shaped membrane serves as a boundary between these two regions of the ear. When sound waves travel through the external ear, they strike the tympanic membrane, causing it to vibrate. These vibrations are then transmitted to the ossicles (the small bones of the middle ear) to further relay sound signals to the inner ear.

Understanding the anatomical positioning of the tympanic membrane is critical in various clinical assessments, as its integrity is essential for proper hearing function. If the tympanic membrane is perforated or damaged, it can lead to hearing loss or middle ear infections.

Other structures listed, such as the oval window and round window, play roles in the inner ear's connectivity and function but do not separate the external ear from the middle ear. The Organ of Corti is a part of the cochlea in the inner ear that is essential for converting sound vibrations into nerve impulses but is not involved in the separation of ear regions.