Ear Anatomy and Physiology Test 1 — Questions and Answers
Question 1: The tympanic membrane vibrates as sound waves pass through the ear canal, which in turn causes the ossicles to vibrate. What is the proper order for the ossicles to travel from the tympanic membrane to the oval window?
- malleus, incus, stapes (Correct answer)
- stapes, incus, malleusv
- incus, malleus, stapes
Correct answer: malleus, incus, stapes
The ossicles are three tiny bones in the middle ear that transmit sound vibrations from the eardrum to the inner ear. The proper order of vibration transmission is from the tympanic membrane to the malleus (hammer), then to the incus (anvil), and finally to the stapes (stirrup), which pushes on the oval window.
Question 2: Which of the following DOES NOT limit the tympanum and ossicles' ability to move when an overwhelming noise is present?
- scala vestibuli (Correct answer)
- tensor tympani
- stapedius
Correct answer: scala vestibuli
The tensor tympani and stapedius muscles are located in the middle ear and contract in response to loud noises, stiffening the tympanic membrane and ossicles to reduce sound transmission. The scala vestibuli, however, is a fluid-filled chamber within the cochlea of the inner ear and is not involved in limiting the physical movement of the tympanum and ossicles.
Question 3: Which of the following is damaged by an inner ear infection in a patient?
- ossicles
- tympanic membrane
- cochlea (Correct answer)
Correct answer: cochlea
The cochlea is the primary auditory organ located in the inner ear, responsible for converting sound vibrations into electrical signals. Infections of the inner ear, such as labyrinthitis, directly affect the cochlea and vestibular system, leading to symptoms like hearing loss and dizziness. The ossicles and tympanic membrane are part of the middle ear.
Question 4: The stapes is attached to one side of the oval window, while the cochlea's _________ is attached to the other.
- scala tympani
- scala vestibuli (Correct answer)
- scala media
Correct answer: scala vestibuli
The stapes, the innermost ossicle, is attached to the oval window, which is the entry point to the inner ear. On the other side of the oval window, within the cochlea, lies the scala vestibuli. The stapes pushes against the perilymph fluid in the scala vestibuli, initiating the pressure wave that travels through the cochlea.
Question 5: The _________ cochlear tube is the ONLY one where perilymph does NOT flow.
- scala tympani
- scala vestibuli
- scala media (Correct answer)
Correct answer: scala media
The cochlea contains three main fluid-filled compartments: the scala vestibuli and scala tympani, both filled with perilymph, and the scala media (or cochlear duct). The scala media is unique because it is the only one filled with endolymph, a fluid with a distinct ionic composition crucial for the function of the organ of Corti.
Question 6: Between the _________ and the __________, the cochlea's basilar membrane can be found.
- scala vestibule; scala media
- scala vestibule; scala tympani
- scala tympani; scala media (Correct answer)
Correct answer: scala tympani; scala media
Within the cochlea, the basilar membrane is a crucial structure that supports the organ of Corti. It is situated between the scala tympani and the scala media. Vibrations transmitted through the fluid cause the basilar membrane to move, which in turn stimulates the hair cells in the organ of Corti.
Question 7: The hearing organ is thought to be the organ of Corti. What location is it in?
- scala tympani
- scala vestibuli
- scala media (Correct answer)
Correct answer: scala media
The organ of Corti, often referred to as the 'hearing organ,' is located within the scala media (or cochlear duct) of the cochlea. This highly specialized structure contains the hair cells that are responsible for transducing mechanical sound vibrations into electrical signals that are sent to the brain for interpretation.
Ear Anatomy and Physiology Test 1
The tympanic membrane vibrates as sound waves pass through the ear canal, which in turn causes the ossicles to vibrate.
What is the proper order for the ossicles to travel from the tympanic membrane to the oval window?