Physiology Flashcards
Physiologically, the middle ear, containing the three ossicles, serves primarily to?
Amplify the energy of sound waves entering the ear
Structure that allows air pressure in the middle ear to equilibrate with atmospheric pressure
Eustachian tube
When stimulated by sound vibrations, inner hair cells (IHCs) of the Organ of Corti release this neurotransmitter onto auditory nerve fibers
Glutamate
The VII cranial nerve innervates this middle ear muscle.
Stapedius Muscle
The coiled, fluid-filled cavity within the bony labyrinth of the inner ear, where the hearing (auditory) structures of the inner ear are located is referred to as the
cochlea
What is the function of the ossicles?
Transmit vibrations from the tympanic membrane to the oval window of the bony labyrinth.
Fluid in the membranous labyrinth within the bony labyrinth that surrounds sensory receptors of the inner ear.
endolymph
-In order for inner hair cells to function properly, the tips of their stereocilia must be bathed in endolymph, which has an exceptionally high potassium ion (K+) concentration, creating a strong electrochemical gradient (large difference in voltage) from the tip to base of a hair cell. This electrochemical gradient provides the energy that allows the hair cell to function.
Perilymph flows in all the following cochlear tubes EXCEPT the __________.
scala media
Which muscles restricts the movement of the tympanum and the ossicles if an excessive noise occurs?
stapedius muscle and the tensor tympani muscle
What is the role of outer hair cells?
enhance the receptors of the inner hair cells, increasing their sensitivity to sound intensity
Protein and calcium carbonate masses embedded in a gelatinous substance that covers hair cells in the utricle and in the saccule
otoliths
This structure connects the nasopharynx with the tympanic cavity.
eustachian tube
