Sensory System - Hearing Flashcards
The structures for hearing also coordinate balance.
True or Fasle
True
What are the 3 parts of the ear?
- outer ear
- middle ear
- inner ear (labyrinth)
The external auditory canal contains glands that excrete ______. a wax the repels insects
cerumen
The middle ear forms the tympanic cavity. What does the tympanic cavity contain?
Malleus
incus
stapes
The malleus, incus and stapes are known together as ________
Ossicles
What is the function of the ossicles?
To transmit movement of the tympanic membrane to the oval window
The tympanic cavity opens into the pharyngotympanic tube. The pharyngotympanic tube leads to the _______.
nasopharnyx
Where are the sensory receptors for hearing located?
The inner ear
The inner ear is found the in the ______ bone
temnporal
The inner ear is formed of a bony ________
labyrinth
The bony labyrinth is covered with _______
endostium
Name the 3 parts of the bony labyrinth
- cochlea
- vestibule
- semicircular canals
The bony labyrinth contains a membranous labyrinth.
True or False
True
The cochlear duct is a membranous labyrinth in the ______ which transduces sound.
cochlea
The utricle and accuse are mambraneous labyrinth in the _______ which transduce head posture
vestibule
the semicircular ducts are the membraneous labyrinth in the _______ canals which transduce head movements
semicircular
The membranous labyrinth contains a liquid called ________ that is similar to intracellular liquid and which is formed by the star vascular of the membrane
endolymph
between the walls of the bony labyrinth and membranous labyrinth, there is _____, a liquid similar to extracellular or cerebrospinal fluid
perilymph
What causes sounds?
changes in air pressure
Sound waves have a _____ and ______
sound waves have an amplitude and frequency
A large amplitude wave corresponds with a ____ sound while a small amplitude wave correspond with a _____ sound.
large amplitude = large sound
small amplitude = small sound
Sound intensity is measured in decibels (dB). The threshold for hearing is ____ dB
0 dB
Normal conversation can be heard at a ___ dB
50 dB
While a rock concert is measured at ___ dB
90 dB
___ db is the threshold at which we will feel pain.
130 dB
A short duration wave corresponds to a _____ frequency sound ( a high pitch)
short duration wave = high frequncy
A long duration wave corresponds to a ____ frequency sound (low pitch)
long wave = low frequency
Sound waves are variations in _______
air pressure
Explain how sound travels through the ear.
Waves enter through the external auditory canal and apply pressure to the tympanic membrane. Movements in the TM are transmitted to the malleus, incus and stapes, which strike the oval window, and this induces waves in the perilymph, where the energy of the waves will bulge the membrane
Movement of the elastic window enduces waves in the perilymph that can propagate through the _____ vestibule, around the ______ and through the ____ tympani and this ends at the round window.
Movement of the elastic window enduces waves in the perilymph that can propagate through the scala vestibule, around the helicotrema and through the scala tympani and this ends at the round window.
The waves enduce ____ of the cochlear duct and its sensory structure.
oscillations
The sensory structures in the cochlear duct are called the _____ organ of the corti
spriral
The spriral organ of the corti lies on the basilar membrane which extends from the base of the cochlear duct to _______ or ________
the apex or helicotrema
The highest frequency sound vibrates the base of the ______ membrane
basilar
The lowest frequency sound vibrates the ___
apex
There are muscles on the first and last ossicle (malleous and stapes) which are recruited 40ms after the beginning of a strong sound to _____ the amplitude of the sound
reduce
The spiral organ rests on the ______ membrane
basilar
The spiral organ is composed of _______ cells and sensory ____ cells
supporting cells and sensory hair cells
The supporting cells and sensory hair cells contain stereocilia that are attacted at the tectorial membrane.
True or False
True
The outer hair cells are stimulated by ___ fibres
efferent
The inner hair cells detect _____
sound
information is relayed to the contralateral superior olive which relays to the inferior colliculus and the thalamus which relays information to the ____ in the temporal lobe
cortex
There are 2 kinds of deafness:
- Conduction deafness
- sensorineural deafness
Explain conduction deafness
problem with the mechanical transmission
Explain Sensorineural deafness
Problem with transmission of electrical activity
If a patient can only hear the sound from a tuning fork when it is placed on the temporal bone then one can conclude that there is conduction deafness. Why?
Because the patient can only hear the vibrations of the tuning fork when they are transmitted it makes contact with the temporal lobe and the hair cells are stimulated
What does tonotopic organization mean
There is an orderly numerical organization of sound frequencies reaching neighbouring areas
Low frequencies are anterior in primary auditory cortex of the temporal lobe.
True or False
True
Where is sound localized?
The auditory cortex
how is sound localized by the auditory cortex
the temporal difference between the arrival of sound in the two ears and by the difference in intensity of sound that enters the ear
Sound coming from the right will reach the left ear first and will be stronger in this ear
True or False
False
sound coming from the right will reach the right ear first.
