PMS - Special Senses (Hearing, Taste, and Smell) Exam
1. How are vibrations transmitted across the middle ear?: Via three small bones (ossicles);
Malleus: attached to TM and moves with incus
Incus
Stapes: faceplate lies against the membranous labyrinth of the cochlea in the opening of the oval window
2. What is the role of tensor tympani muscle?: - keeps the TM tensed, ensuring eflcient
transmission of vibrations
3. What does bone conduction of sound require?: - a special electro-mechanical sound ampli-
fying device for effective hearing via bone conduction
4. Is air or bone conduction more snesitive?: - Air condition in a normal person
5. Describe the structure of the cochlea.: - coiled system of three fluid-filled tubes: scale vesitbuli,
scala media, scala tympani
6. How do sound vibrations enter the scala vestibuli?: - through the oval window at the stapes
and creates a traveling wave along the basilar membrane
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, 7. What type of vibration do high frequency sounds cause of the basilar mem-
brane?: - maximum vibration near the base (oval window)
8. What type of vibration do low frequency sounds cause of the basilar mem-
brane?: - maximum vibration near the apex (helicotrema)
9. How does the basilar membrane discriminate frequency?: - according to the place
principle, as it varies in stiffness and width along its length
10. What is the organ of Corti?: - located on the basilar membrane
- contains hair cells that are sensory receptors for hearing
11. How are hair cells activated?: 1. vibration of the basilar membrane causes stereocilia on hair celsl to
bend against tectorial membrane
2. bending of stereocilia in one direction opens ion channels, which allows influx of potassium and leads to depolar-
ization, which opens voltage gated calcium channels and the release of neurotransmitters (glutamate)
3. bending in opposite direction causes hyperpolarization
12. What is responsible for the depolarization of action potentials in the ear?: -
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1. How are vibrations transmitted across the middle ear?: Via three small bones (ossicles);
Malleus: attached to TM and moves with incus
Incus
Stapes: faceplate lies against the membranous labyrinth of the cochlea in the opening of the oval window
2. What is the role of tensor tympani muscle?: - keeps the TM tensed, ensuring eflcient
transmission of vibrations
3. What does bone conduction of sound require?: - a special electro-mechanical sound ampli-
fying device for effective hearing via bone conduction
4. Is air or bone conduction more snesitive?: - Air condition in a normal person
5. Describe the structure of the cochlea.: - coiled system of three fluid-filled tubes: scale vesitbuli,
scala media, scala tympani
6. How do sound vibrations enter the scala vestibuli?: - through the oval window at the stapes
and creates a traveling wave along the basilar membrane
1/7
, 7. What type of vibration do high frequency sounds cause of the basilar mem-
brane?: - maximum vibration near the base (oval window)
8. What type of vibration do low frequency sounds cause of the basilar mem-
brane?: - maximum vibration near the apex (helicotrema)
9. How does the basilar membrane discriminate frequency?: - according to the place
principle, as it varies in stiffness and width along its length
10. What is the organ of Corti?: - located on the basilar membrane
- contains hair cells that are sensory receptors for hearing
11. How are hair cells activated?: 1. vibration of the basilar membrane causes stereocilia on hair celsl to
bend against tectorial membrane
2. bending of stereocilia in one direction opens ion channels, which allows influx of potassium and leads to depolar-
ization, which opens voltage gated calcium channels and the release of neurotransmitters (glutamate)
3. bending in opposite direction causes hyperpolarization
12. What is responsible for the depolarization of action potentials in the ear?: -
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