Ears

Ears are complicated structures, most of which is hidden inside the head, and is concerned with not only hearing but also balance. The outer ear's job is to collect sound and protect the sensitive ear drum, which is at the bottom of the ear canal, which can sometimes cause problems by producing too much ear wax, and may need cleaning with special drops or fluid, and never by poking anything down the ear canal, as this can easily make things worse and cause damage. Internally the balance mechanism tells you which way up you are, but can become overwhelmed in travel sickness.