While revising the middle ear muscles, a student notes that each auditory ossicle receives a muscle insertion except one. Which ossicle has no muscle attached to it?

• A Malleus
• B All three ossicles receive a muscle insertion
• C Stapes
• D Incus ✓

Explanation

The tensor tympani inserts into the medial surface of the handle of the malleus, and the stapedius inserts into the neck of the stapes. The incus has no muscle attached to it, which contributes to its vulnerability to displacement in head trauma; traumatic ossicular dislocation most often involves incudostapedial joint separation. This makes the incus the correct key and rules out option B immediately.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.