martin chapter 8 Flashcards
auricle or pinna, what is it?
the visible external part of the ear
external auditory meatus
tubular passage found in each temporal bone
mechanical displacement of the tympanic membrane (produced by changes in sound pressure waves) is transmitted to the inner ear by?
tiny bones termed middle ear ossicles
3 tiny ossicles
1. malleus
2. incus
3. stapes
where is the inner ear transductive machinery located?
in a coiled structure within the temporal bone named cochlea
where are auditory receptors located and how are they called?
in the cochlea
they are called hair cells because they are characterized by a bundle of hair-like stereo cilia on their apical surface.
each auditory receptor is sensitive to a limited frequency range of sounds
from the base of the cochlea to the apex the sound frequency to which a hair cell is most sensitive changes. where are receptors that are most sensitive to higher frequencies located?
in the base of the cochlea
in the apex instead there are hair cells that are most sensitive to lower frequencies
who determines where a sound originates?
CNS auditory neurons based on timing, loudness and spectral characteristics of sound
hair cells are innervated by?
distal processes of bipolar sensory neurons located In the spiral ganglion
the central process of bipolar neurons in the auditory system refers to?
the central process of a bipolar neuron refers to the part of the neuron that carries information toward the central nervous system (CNS).
what do the central processes of the bipolar neurons form?
the cochlear division of the vestibulocochlear nerve (Cranial nerve VIII)
where do the axons of the cochlear division of the vestibulocochlear nerve project?
they project to the ipsilateral cochlear nuclei, located in the rostral medulla
cochlear nuclei consist of:
-dorsal cochlear nuclei
-ventral cochlear nuclei (that have an anterior and posterior subdivisions)
where does the ventral cochlear nucleus project?
it projects bilaterally into the superior olivary complex, a cluster of nuclei in the caudal pons
where do neurons in the superior olivary complex project?
to the inferior colliculus via an ascending pathway called lateral lemniscus
where does the dorsal cochlear nucleus project?
directly into the contralateral inferior colliculus (also via the lateral lemniscus) bypassing the superior olivary complex
which is the site of convergence of all lower brain stem auditory nuclei?
the inferior colliculus
what is wernicke’s area and where is it located?
is an area of the cerebral cortex involved in understanding speech. it is located in the superior temporal gyrus
where is Broca’s areas?
located in the inferior frontal gyrus
a cortical area fundamental for the production of speech
what is the thalamic auditory relay nucleus of the ascending auditory pathway?
the medial geniculate nucleus
where does the medial geniculate nucleus project?
to the primary auditory cortex, located in the sylvian fissure (also called lateral sulcus, found on the superior surface of the temporal lobe) on Heschl’s gyri
the primary auditory cortex is surrounded by?
secondary auditory areas
where are several higher order auditory areas located?
in the superior temporal gyrus and sulcus. several areas located there are important for understanding speech
where are the auditory sensory organs located?
within the membranous labyrinth
what is the membranous labyrinth made of?
it is made of the cochlea and 5 vestibular sensory organs
1. saccule
2. utricle
and 3 semicircular canals