Anatomy of the Ear Flashcards
Organ of balance; within the inner ear; consists of the Semicircular canals, Utricle and Saccule
Vestibular Apparatus
Part of Vestibular Apparatus; used for perception of ANGULAR acceleration (rotation of head)
Semicircular canals
Parts of Vestibular Apparatus; used for perception of LINEAR acceleration
Utricle & Saccule
The lateral 1/3rd of the External Acoustic Meatus is (bony/cartilaginous) and is lined with skin that produces cerumen (earwax)
Cartilaginous
The medial 2/3rds of the External Acoustic Meatus is (bony/cartilaginous) and is lined with skin that is continuous with the tympanic membrane
Bony
What three cranial nerves contribute to innervating the Auricle and Ear Canal
Trigeminal (V3)
Vagus (CN X)
Facial (CN VII)
Which cranial nerve innervates the central portion of the Auricle and the External Acoustic Meatus
Vagus (CN X)
Small opening in the posterior wall of the Middle Ear; leads to a cavity within the mastoid process
Auditus
The _____________ nerve passes through a bony canal along the posterior wall of the Middle Ear
Facial
A rounded hollow prominence of the medial Middle Ear covered by a nerve plexus; separates middle ear from the inner ear; has the tympanic plexus over it and two windows (oval and round)
Promontory
The Tympanic Plexus in the Middle Ear comes from which cranial nerve and therefore provides sensory innervation from middle ear/eustachian tube?
Glossopharyngeal (CN IX)
Patients with middle ear infections feel the pain via what nerve?
Glossopharyngeal nerve (Tympanic Plexus)
What are the 3 ossicles of the Middle Ear (in order)
Malleus
Incus
Stapes
What are the 2 muscles in the Middle Ear that dampen movements of ossicles to lessen loud sound transmission in order to prevent damage?
Tensor Tympani (at eardrum) Stapedius (at stapes)
Muscle of Middle ear; innervated by Trigeminal (V3); lessens damage from loud sounds by “tensing” the eardrum via attaching to the Handle of the Malleus
Tensor Tympani
Muscle of the Middle Ear; innervated by the Facial nerve; dampens vibrations of the Stapes at the Oval Window
Stapedius
Small branch of the Facial nerve that passes THROUGH the Middle Ear cavity on it’s way to the oral cavity; courses between the Malleus and Incus; Swelling and compression of this nerve during URIs can dampen taste
Chorda Tympani
Central depression of the Tympanic Membrane
Umbo
Reflection of light from the Otoscope at the anteroinferior portion of the Tympanic Membrane (due to the membrane’s orientation)
Cone of Light
Thin portion of the Tympanic Membrane above the Handle of the Malleus
Pars Flaccida (flaccid)
Thick portion of the Tympanic Membrane that makes the majority
Pars Tensa (tense)
Contents of the Bony Labyrinth of the Inner Ear
Cochlea
Vestibule
Semicircular Canals
The ____________________ labyrinth is a series of ducts/sacs suspended WITHIN the bony labyrinth and filled with _____________________
Membranous; endolymph (similar to intracellular fluid)
The membranous labyrinth consists of what 3 inner ear apparati
Cochlear duct
Utricle/Saccule
Semicircular ducts
Specialized structures within the Utricle and Saccule to detect LINEAR movements
Maculae (have hair cells)
Signals detected by the Utricle, Saccule and Semicircular Ducts in the Inner Ear are conveyed via the ____________________ nerve
Vestibular (CN VIII)
Swelling at the base of each semicircular duct; contains special sensory structures called crista
Ampulla
Special sensory structure in the Ampulla of the Semicircular ducts; detects the movement of the surrounding endolymph during rotational movement of the head
Crista
What chamber(s) of the Cochlea have perilymph
Scala Vestibuli
Scala Tympani
What chamber(s) of the Cochlea has endolymph
Scala media (Cochlear duct)
Membrane that separates the Scala Vestibuli and Cochlear Duct
Vestibular membrane
Membrane that separates the Cochlear Duct and the Scala Tympani
Basilar membrane
The Scala Vestibuli and Tympani are continuous at the tip of the Cochlea, called the…
Helicotrema
Transmission of sound waves goes along the perilymph of _______ and displaces the (vestibular/basilar) membrane to manipulate the Organ of Corti within __________.
Basilar; scala media (cochlear duct)
Nerve endings in the Organ of Corti transmits impulses to the CNS via _______ nerve
cochlear nerve (CN VIII)
The pressure wave traveling through the scala tympani eventually dissipates into _______ via _______
tympanic cavity (middle ear); round window