What is the full form of IAC

IAC : Internal Acoustic Canal

IAC stands for internal acoustic canal. It is also known as the internal auditory canal or meatus (IAM). It is located in the petrous part of temporal bone between the inner ear and posterior cranial fossa. It opens to the inside of the cranial cavity, this opening is known as internal acoustic opening or porus acusticus internus. Its outer margins are rounded and smooth. The outer part of the canal is called the fundus, which is subdivided by two thin crests of bone that forms three separate canals for facial and vestibulocochlear nerve branches.

It is a rounded and smooth canal that measures around 8.5 mm in length, around 4 mm in diameter and is filled with spinal fluid and lined by dura. It contains three important nerves that include the auditory nerve, the facial nerve, and the vestibular nerves. It provides passage to these three nerves to pass from inside the skull to structures of the inner ear and face. The facial and vestibulocochlear nerves transmit information to the brain. So, internal acoustic canal is an important part in the cranial cavity that helps perform various vital function.