The entrance to the external acoustic meatus is located in which part of the temporal bone?

• A. Tympanic part
• B. Petrous part
• C. Squamous part
• D. Mastoid part

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by understanding the anatomy of the temporal bone, which is divided into four main parts: the squamous part, tympanic part, mastoid part, and petrous part. Each part has distinct features and functions.
2. Step 2: Focus on the external acoustic meatus, which is the canal leading to the eardrum and middle ear. It serves as the pathway for sound waves to reach the tympanic membrane.
3. Step 3: Identify which part of the temporal bone surrounds or contributes to the formation of the external acoustic meatus. The tympanic part of the temporal bone is specifically associated with the external acoustic meatus.
4. Step 4: Compare the other options (petrous, squamous, and mastoid parts) to confirm they do not directly form or surround the external acoustic meatus. For example, the petrous part houses the inner ear structures, the squamous part forms the flat portion of the temporal bone, and the mastoid part contains air cells.
5. Step 5: Conclude that the entrance to the external acoustic meatus is located in the tympanic part of the temporal bone, based on its anatomical relationship and function.