The tensor tympani muscle inserts into the medial surface of the handle of malleus. Its primary mechanical action when it contracts is to:

• A Pull the malleus medially, tensing the tympanic membrane ✓
• B Rotate the malleus laterally, relaxing the tympanic membrane
• C Compress the incudostapedial joint to reduce stapes excursion
• D Displace the umbo posteriorly to increase resonant frequency

Explanation

The tensor tympani, innervated by the medial pterygoid branch of CN V3, inserts on the manubrium of malleus. Contraction pulls the handle of malleus medially and anteriorly, increasing tension across the tympanic membrane. This increases the stiffness of the ossicular chain, attenuating low-frequency sound transmission — the acoustic reflex principle. Options B and C describe erroneous mechanics; option D mischaracterises the direction of displacement.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.