Hearing Loss Ear Anatomy and Physiology 3 — Questions and Answers
Question 1: Which three tiny bones make up the ossicular chain of the middle ear?
- Malleus, incus, stapes (Correct answer)
- Cochlea, utricle, saccule
- Hammer, cochlea, anvil
- Stapes, pinna, tragus
Correct answer: Malleus, incus, stapes
The malleus, incus, and stapes form the ossicular chain that conducts vibrations.
Question 2: What is the main purpose of the ossicles' lever action and area ratio?
- Reducing sound to protect the brain
- Amplifying and matching impedance to fluid (Correct answer)
- Filtering out low frequencies
- Generating earwax
Correct answer: Amplifying and matching impedance to fluid
The ossicles boost sound pressure to overcome the impedance of inner ear fluid.
Question 3: The basilar membrane responds to high-frequency sounds most strongly at which location?
- Apex of the cochlea
- Base of the cochlea (Correct answer)
- Helicotrema
- Round window
Correct answer: Base of the cochlea
The stiff, narrow base of the cochlea is tuned to high frequencies (tonotopic organization).
Question 4: Which muscle contracts to dampen loud sounds by stiffening the stapes?
- Tensor tympani
- Stapedius (Correct answer)
- Buccinator
- Masseter
Correct answer: Stapedius
The stapedius muscle contracts during the acoustic reflex to reduce transmission of loud sounds.
Question 5: The cochlea is divided into how many fluid-filled compartments?
- One
- Two
- Three (Correct answer)
- Four
Correct answer: Three
The cochlea has three chambers: scala vestibuli, scala media, and scala tympani.
Question 6: What primarily produces cerumen (earwax) in the external canal?
- Ceruminous glands (Correct answer)
- Hair cells
- Sebaceous bone
- Cochlear duct
Correct answer: Ceruminous glands
Ceruminous glands in the outer ear canal secrete cerumen that protects and lubricates.
Question 7: The round window's main function is to:
- Collect sound waves
- Allow fluid pressure to dissipate (Correct answer)
- Produce endolymph
- Sense gravity
Correct answer: Allow fluid pressure to dissipate
The flexible round window bulges to relieve pressure as the oval window pushes fluid inward.
Hearing Loss Ear Anatomy and Physiology 3
Which three tiny bones make up the ossicular chain of the middle ear?