Special Sense Organs Part 5 Flashcards
What two arteries carry the blood supply to the middle ear?
anterior tympanic branch of the internal maxillary artery and the tympanic branch of the internal carotid artery
What nerve provides the sensory supply to the middle ear?
tympanic nerve of CN IX
What nerves provide motor supply to the middle ear?
Nerve to the stapedius of the facial nerve and the medial pterygoid nerve of the mandibular division (supplies tensor tympani)
What nerves provide sympathetic supply to the middle ear?
caroticotympanic nerves
What nerves carry vasomotor and secretomotor fibers from the superior cervical ganglion to the middle ear by way of the internal carotid plexus?
caroticotympanic nerves
What are the two parts of the labyrinth (inner ear)?
bony and membranous
What is the enclosure for the membranous labyrinth?
bony labyrinth
What is the membranous labyrinth surrounded by within the bony labyrinth?
perilymph
What are the 3 parts of the bony labyrinth?
cochlea, vestibule, and semicircular canals
What part of the bony labyrinth is shaped like a snail shell and contains the cochlear duct?
cochlea
What part of the bony labyrinth contains the saccule and utricle?
vestibule
What part of the bony labyrinth is divided into the lateral, anterior, and posterior and contains the semicircular ducts?
semicircular canals
T/F: the membranous labyrinth is bathed in endolymph and contains perilymph.
False; bathed in perilymph, contains endolymph
What are the 2 main parts of the membranous labyrinth?
cochlear labyrinth and vestibular labyrinth
T/F: the cochlear labyrinth contains the utricle, saccule, semicircular ducts, utricosaccular duct, endolymphatic duct, endolymphatic sac, and ductus reuniens.
False; these are contained in the vestibular labyrinth; the cochlear labyrinth only contains the cochlear duct
The bony part of the cochlea consists of a tube coiled around a cones shaped central bony structure call what?
the mediolus
How many times does the cochlea wrap around the modiolus?
2.5-2.75 times
What is the term for the apex of the cochlea which is directed anteriolaterally?
the cochlear cupula
What is the name of the bony ridge that connects the cochlea to the modiolus?
the lamina of modiolus
What 3 channels make up the cochlea?
the cochlear duct, the scala vestibuli and the scala tympani
Where does the cochlear duct end?
at the apex of the cochlea
How do the scala tympai and the scala vestibuli communicated with each other?
at the apex through a channel called the helicotrema
T/F: the scala vestibuli is above the cochlear duct and filled with endolymph.
False; filled with perilymph
What forms the base of scala vestibuli allowing for vibrations to be transmitted from the stapes into the scala vestibuli?
oval window
The scala tympani is below the cochlear duct and vibrations from the scala vestibuli pass to the scala tympani via what structure? What is the base of the scala tympani?
helicotrema;
round window
What structure is in the middle of the bony labryrinthfilled with endolymph with the scala vestibule above and the scala tympani below?
cochlear duct
What structure is attached to the lamina of the modiolus, anchored to the outer wall of the cochlea by the spiral ligament, and separated from the scala vestibuli by the vestibular membrane?
cochlear duct
What separates the cochlear duct from the scala tympani?
the basilar or spiral membrane
Where is the spiral organ located? what is it attached to?
on the floor of the cochlear duct, attached to the basilar/spiral membrane
What structure of the inner ear has numerous hair-like projections superiorward that are sensitve to frequency and amplitude of sound waves that enter cochlea?
spiral organ
What are the hair cells of the spiral organ covered by?
tectorial membrane
What are the hair like projections of the spiral organ projecting from?
basilar/spiral membrane
Info is conveyed from receptor cells in the inner ear to the primary sensory neurons. Where are the cell bodies of these neurons located?
in the spiral ganglion
