Download Study guide for exam 2

SPPA 6030: Study Guide for Exam 2
Notes: This study guide is intended to give you a general idea of some of the kinds of questions that
might appear on the exam, and to help you organize your studying. It is not intended to cover all of
the topics that might be appear on the exam. However, some of the exam questions may be taken
almost verbatim from the study guide. In addition to the kinds of questions that are shown below,
there may also be multiple choice questions, matching items, and diagrams that you would be
asked to label. NOTE: The study guide is based on a guess about how much material we will
cover prior to the exam. There may be material covered here which we do not get to and
which, therefore, will not be on the exam. For example, I think it’s unlikely that we will get to
the central auditory system, although this topic is covered on the study guide. If you are
unsure, ask me.
1. What are the three functional subsystems of the auditory system? What functions are performed
by each subsystem?
2. What does it mean to say that there is an impedance mismatch between the outside air and the
inner ear? How large is this mismatch: (a) expressed as a ratio, and (b) expressed on a decibel
scale? How does the middle ear overcome this mismatch?
3. What does it mean to say that the auditory system is a spectrum analyzer? Give a general
explanation of how the auditory system performs spectrum analysis.
4. What is the acoustic reflex? What muscles participate in this reflex? What is thought to be the
purpose of this reflex?
5. Where is the Eustachian tube located? What are the functions of the Eustachian tube?
6. What are the six surfaces of the tympanic cavity, and what structures are located on each
surface?
7. The tympanic membrane is composed of what three layers?
8. What is a transducer? What transduction functions are performed by the auditory system?
9. Explain what causes the "pop" that you hear when riding down (or up) an elevator in a tall
building.
10. The labyrinth contains what two sensory systems?
11. The membranous labyrinth portion of the cochlea consists of what two membranes?
12. Assuming an average length of 2.5 cm for the external auditory meatus (EAM), what is the
lowest resonant frequency of this canal? Draw the frequency-response for the EAM showing
the two lowest resonances.
SPPA 6030, Study Guide for Exam 2
2
13. What is the maximum firing rate that a neuron can sustain for a short period of time? What is
the maximum firing rate that a neuron can sustain for an extended period of time? What do
these firing-rate limits have to do with absolute and relative refractory periods? Why are these
facts important for understanding frequency analysis by the auditory system?
14. How do the physical characteristics of the basilar membrane vary from the base of the cochlea
to the apex? Why is this fact important for understanding frequency analysis by the auditory
system?
15. What anatomical structure lies immediately above the superior surface of the tympanic cavity?
16. What portion of the malleus attaches to the tympanic membrane?
17. What effects do the contraction of the tensor tympani and stapedius muscles have on the
structures of the middle ear?
18. How does the Eustachian tube of an infant or young child compare with that of an adult? Why
are these anatomical differences important?
19. The __________________, a gap at the apex of the cochlea, allows the fluid in the vestibular
canal to communicate with the fluid in the tympanic canal.
20. This material is a fatty substance that coats the fibers of some but not all neurons. Fibers that
contain this substance transmit neural signals more rapidly than uncoated fibers.
21. Give an example that illustrates the difference between force and pressure. Why is this
distinction important to the functioning of the auditory system?
22. Explain the two schemes that might be used by the auditory system to code frequency.
23. Draw graphs showing the amount of 8th-nerve electrical activity as a function of position along
the basilar membrane for: (a) a high-frequency signal, (b) a mid-frequency signal, and (c) a
low-frequency signal. What, if anything, does this graph have to do with Fourier analysis?
24. Draw a graph showing how voltage varies over time in the generation of a neural spike
potential. Label your graph and provide a scale for the voltage axis.
25. What does it mean to say that the auditory pathway exhibits tonotopic organization?
26. The peripheral auditory system consists of everything from the pinna up to and including the
_________________________.
27. The central auditory system consists of structures in the ______________________________
and the ______________________________.
28. What do neurons have in common with toilets?
SPPA 6030, Study Guide for Exam 2
29. According to the Hallowell Davis model of hair-cell function, hair cells form part of an
electrical circuit. Draw this circuit and briefly explain how it works.
30. A hair cell channel consists of ____________________________.
31. What specific component of the hair cell channel is responsible for transduction?
32. Most auditory nerve fibers are: (a) afferent, or (b) efferent.
33. Most auditory nerve fibers synapse on: (a) IHCs, (b) OHCs, or (c) IHCs and OHCs about
equally.
34. The cochlea contains roughly this many channels __________________.
35. It is not uncommon for a disease process to affect both the sense of hearing and the sense of
balance. Why might this be the case?
Terms for Exam 2 (Anatomy and Physiology)
Note: Items that are separated by slashes are alternate names for the same structure.
transducer
conductive mechanism
sensorineural mechanism
central auditory system
acoustic nerve/auditory nerve/8th cranial nerve
vestibular branch of the 8th nerve
cochlear branch of the 8th nerve
pinna
helix
antihelix
tragus
antitragus
concha
ear lobe
external auditory meatus/ear canal
sebaceous glands
cerumen
tympanic membrane/ear drum
tympanic sulcus
Shrapnell's membrane/pars flaccida
pars tensa
umbo
tympanic cavity/middle ear cavity
jugular vein
3
SPPA 6030, Study Guide for Exam 2
attic/epitympanic recess
tympanic cavity proper
oval window
annular ligament
round window
internal tympanic membrane
facial nerve/7th cranial nerve
promontory
pyramidal eminence
stapedius muscle
tensor tympani
Eustachian tube/auditory tube
malleus - manubrium, head, neck
incus - short process, body, long process
stapes - head, neck, posterior crus, anterior crus, footplate
impedance (resistance, mass reactance, capacitive reactance)
impedance mismatch
force
pressure
acoustic reflex
intensity control theory
labyrinth
bony labyrinth
membranous labyrinth
helicotrema
internal auditory meatus
vestibular mechanism
otolith system
semicircular canals
ampulla
utricle
saccule
cristae
maculae
angular acceleration/"head motion"
linear acceleration
perilymph
endolymph
cochlea
vestibule
basal, medial, and apical turns of the cochlea
modiolus
basilar membrane
Reissner's membrane
organ of Corti
spiral lamina/bony spiral lamina
4
SPPA 6030, Study Guide for Exam 2
scala vestibuli/vestibular canal
scala tympani/tympanic canal
scala media/cochlear duct/cochlear partition
stria vascularis
tectorial membrane
Dieter's cells
phalangeal process
limbus
inner hair cells
outer hair cells
cilia
cuticle/cuticular plate
tunnel of Corti
rods of Corti
neuron
dendrite
axon
cell body
afferent process
efferent process
myelin
spike potential
depolarization
absolute refractory period
relative refractory period
ganglion
nucleus
traveling wave
place theory/place principle
frequency theory/synchrony theory
volley principle
tonotopic organization
5