What is the pinna?

The pinna refers to the outer visible part of the ear, which is responsible for capturing sound waves and directing them into the auditory canal. This structure is made up of cartilage and skin, and its unique shape helps in sound localization—allowing the brain to perceive where a sound is coming from. It is important in the overall auditory system as it collects and funnels sounds from the environment to the inner workings of the ear, playing a crucial role in hearing.

The other choices represent different anatomical structures or systems that do not pertain to the ear's outer structure. The throat is unrelated to the pinna, and neither the bony structures of the ear nor types of blood vessels connect directly to the definition of the pinna.