Hearing & Vestibular Sense Flashcards
Outer ear consists of:
Pinna (auricle)
External auditory canal
Tympanic membrane
Middle ear consists of:
The ossicles: malleus and staples
Inner ear consists of:
Bony labyrinth
Pinna function
Channels sound waves into the external auditory canal
External auditory canal directs:
The sound waves to the tympanic membrane (eardrum)
Louder sounds = _____ intensity
Greater
What separates the outer ear from the middle ear
Tympanic membrane
Ossicles
Found in the middle ear
Helps transmit and amplify the vibrations from the tympanic membrane to the inner ear
Malleus (hammer)
Attached to the tympanic membrane
Acts on the incus (anvil) which acts on the staples (stirrup)
Cochlea
Entrance to the inner ear
Staples rest on it
Ossicles is made up of 3 parts. What are they ?
Staples
Malleus
Incus
The middle ear is connected to the nasal cavity via what?
Eustachian tube
Eustachian tube function?
Helps equalize pressure between the middle ear and the environment
Bony labyrinth contains:
Cochlea
Vestibule
Semicircular canals
(3) parts an ear is divided into
Inner, middle and outer ear
What thin layer of fluid simultaneously transmits vibrations from the outside world and cushions the inner ear structures ?
Perilymph
Cochlea
Detects sound
Spiral shaped organ divided into 3 parts called Scalae
Organ of corti
Actual hearing apparatus
Contains thousands of hair cells bathed in endolymph
Basilar membrane
Thin flexible membrane under the organ of corti
Tectorial membrane
Immobile membrane on top of the organ of corti
Sound enters the cochlea through the oval window and causes vibrations in the Perilymph which are transmitted to which membrane ?
Basilar membrane
Round window
A membrane covered hole in the cochlea that permits the Perilymph to actually move within the cochlea
Hair cells on the organ of corti function ?
Converts the physical stimulus into an electrical signal which is carried to the CNS by the auditory (vestibulocochlear) nerve
Bony labyrinth is filled with
Perilymph
Utricle and saccule
Is in the vestibule that is a portion of the bony labyrinth
Detect linear acceleration
Contain modified hair cells covered with otoliths (which resist motion as the body accelerates)
Semicircular canals
Detect rotational acceleration
Auditory pathway
Cochlea ➡️ vestibulocochlear nerve and medial geniculate nucleus (MGN) ➡️ auditory cortex in the temporal lobe
Auditory group is found in what lobe?
Temporal
Superior olive
Localizes the sound
Inferior colliculus
Helps keep the eyes fixed on s point while the head is turned
Involved in the startle reflex
Swaying of hair cells cause what to open?
Ion channels
Which cause receptors potentials
