Facial Nerve Anatomy Flashcards
The ___ is the space medial to the TM and it extends from the Eustachian tube opening anteriorly to the FN posteriorly.
The mesotympanum is the space medial to the TM and it extends from the Eustachian tube opening anteriorly to the FN posteriorly.
The mesotympanum is the space medial to the TM and it extends from the ___ anteriorly to the ___ posteriorly.
The mesotympanum is the space medial to the TM and it extends from the Eustachian tube opening anteriorly to the FN posteriorly.
The ___ is medial to the ET opening, and the ___ occupies the semicanal superior and parallel to the ET.
The carotid a. is medial to the ET opening, and the tensor tympani muscle occupies the semi canal superior and parallel to the ET.
The ___ forms the medial wall of the mesotympanum, and is marked posteriorly by the oval window superiorly.
The cochlear promontory forms the medial wall of the mesotympanum, and is marked posteriorly by the oval window superiorly.
The cochlear promontory forms the medial wall of the mesotympanum, and is marked posteriorly by the ___ superiorly.
The cochlear promontory forms the medial wall of the mesotympanum, and is marked posteriorly by the oval window superiorly.
The cochlear promontory is occupied by the ___ and ___ inferiorly.
The cochlear promontory is occupied by the stapes and round window inferiorly.
The mesotympanum extends into a recess that lies posterior to the oval and round windows and medial to the vertical FN, known as the _____.
The mesotympanum extends into a recess that lies posterior to the oval and round windows and medial to the vertical FN, known as the sinus tympani.
The ___ may harbor occult cholesteatoma.
The sinus tympani may harbor occult cholesteatoma.
The pyramidal eminence connects the ___ tendon to the ___ and is located in front of (anterior) to the second genu of the FN as it transitions from the tympanic (horizontal) to mastoid (vertical) segment.
The pyramidal eminence connects the stapedial tendon to the stapes superstructure and is located in front of (anterior) to the second genu of the FN as it transitions from the tympanic (horizontal) to mastoid (vertical) segment.
The ___ of the TM marks the inferior limit of the mesotympanum and superior limit of the hypotympanum.
The inferior annulus of the TM marks the inferior limit of the mesotympanum and superior limit of the hypotympanum.
The hypotympanum is limited inferiorly by the ___, and may extend inferomedially to the cochlea.
The hypotympanum is limited inferiorly by the jugular bulb, and may extend inferomedially to the cochlea.
A single vessel supplies the ___, making it susceptible to aseptic necrosis, for example, as a result of middle ear infection.
A single vessel supplies the long process of incus, making it susceptible to aseptic necrosis, for example, as a result of middle ear infection.
The ___ and ___ are otoscopic landmarks for the inferior limit of the epitympanum.
The lateral process of the malleus and spines of the Notch of Rivinus are otoscopic landmarks for the inferior limit of the epitympanum.
The epitympanum is further divided into ___, located medial to pars flaccida and lateral to the head and neck of the malleus.
The epitympanum is further divided into Prussak space, located medial to pars flaccida and lateral to the head and neck of the malleus.
The geniculate ganglion and first genu of the FN are medial to a bony cul-de-sac of the mesotympanum (located anterior to the attic and superior to eutsachian tube opening), known as the _____.
The geniculate ganglion and first genu of the FN are medial to a bony cul-de-sac of the mesotympanum (located anterior to the attic and superior to eutsachian tube opening), known as the supratubal recess (STR).
The geniculate ganglion and first genu of the FN are medial to a bony cul-de-sac of the mesotympanum (located anterior to the attic and superior to eutsachian tube opening), known as the _____.
The geniculate ganglion and first genu of the FN are medial to a bony cul-de-sac of the mesotympanum (located anterior to the attic and superior to eutsachian tube opening), known as the supratubal recess (STR).
The posterior opening of the STR is marked by the ___ inferiorly and the ___ superiorly, an incomplete bony septum oriented in the coronal plane and based on the tegmen.
The posterior opening of the STR is marked by the cochleariform process inferiorly and the “cog” superiorly, an incomplete bony septum oriented in the coronal plane and based on the tegmen.
The _____ segment of the FN projects posteriorly at a slight inferior incline, and skims superior to the cochleariform process, which serves as a landmark for the mid portion of the tympanic segment of the FN.
The tympanic segment of the FN projects posteriorly at a slight inferior incline, and skims superior to the cochleariform process, which serves as a landmark for the mid portion of the tympanic segment of the FN.
The fallopian canal serves as the bony superior limit of the ___; however, in 55% of cases, the FN is partially exposed because of bony dehiscence.
The fallopian canal serves as the bony superior limit of the oval window niche; however, in 55% of cases, the FN is partially exposed because of bony dehiscence.
The FN is most vulnerable to iatrogenic injury just proximal to the ___ and in its ___ path.
The FN is most vulnerable to iatrogenic injury just proximal to the second genu and in its vertical path.
When the tegmen tympani (roof of the epitympanum) is dehiscent, ectopic arachnoid granulations on the bony floor of the middle fossa may, over time, erode into the mastoid as a result of pulsations of CSF, and cause a ____ that may leak spontaneous CSF fluid to generate middle ear effusions, rhinorrhea, or otorrhea.
When the tegmen tympani (roof of the epitympanum) is dehiscent, ectopic arachnoid granulations (arachnoid pits) on the bony floor of the middle fossa may, over time, erode into the mastoid as a result of pulsations of CSF, and cause an cephalocele that may leak spontaneous CSF fluid to generate middle ear effusions, rhinorrhea, or otorrhea.
The lateral and superior SCCs form the medial walls of the posterior epitympanum at its opening into the _____.
The lateral and superior SCCs form the medial walls of the posterior epitympanum at its opening into the antrum, known as the aditus ad antrum.
The___ forms a prominence at the inferior aspect of the aditus ad antrum, where impacted cholesteatoma, if present, can erode the otic capsule and lead to formation of a perilymphatic fistula over time.
The lateral SCC forms a prominence at the inferior aspect of the aditus ad antrum, where impacted cholesteatoma, if present, can erode the otic capsule and lead to formation of a perilymphatic fistula over time.
The lateral SCC forms a prominence at the inferior aspect of the aditus ad antrum, where impacted cholesteatoma, if present, can erode the otic capsule and lead to formation of a ___ over time.
The lateral SCC forms a prominence at the inferior aspect of the aditus ad antrum, where impacted cholesteatoma, if present, can erode the otic capsule and lead to formation of a perilymphatic fistula over time.
The ___ genu of the FN hugs the ant-inf aspect of the lateral SCC.
The second genu of the FN hugs the ant-inf aspect of the lateral SCC.
The _____ fibers of the FN supply input to striated muscles of facial expression: stapedius, stylohyoid, and posterior belly of the digastric.
The special visceral efferents of the FN supply input to striated muscles of facial expression: stapedius, stylohyoid, and posterior belly of the digastric.
_____ fibers form the nervous intermedius, which innervates the lacrimal gland and seromucinous glads of the nasal cavity, via the GSPN and pterygopalatine ganglion, and the submandibular and sublingual glands via the chorda tympani, tonsillar fossae and palate via the GSPN.
General visceral efferent fibers form the nervous intermedius, which innervates the lacrimal gland and seromucinous glads of the nasal cavity, via the GSPN and pterygopalatine ganglion, and the submandibular and sublingual glands via the chorda tympani, tonsillar fossae and palate via the GSPN.
General visceral efferent fibers form the nervous intermedius, which innervates the ____ and seromucinous glands of the nasal cavity, via the GSPN and pterygopalatine ganglion, and the ___ and ___glands via the chorda tympani, tonsillar fossae and palate via the GSPN.
General visceral efferent fibers form the nervous intermedius, which innervates the lacrimal gland and seromucinous glands of the nasal cavity, via the GSPN and pterygopalatine ganglion, and the submandibular and sublingual glands via the chorda tympani, tonsillar fossae and palate via the GSPN.
General visceral efferent fibers form the nervous intermedius, which innervates the lacrimal gland and seromucinous glands of the nasal cavity, via the ___ and ___ ganglion, and the submandibular and sublingual glands via the ___, tonsillar fossae and palate via the ___.
General visceral efferent fibers form the nervous intermedius, which innervates the lacrimal gland and seromucinous glands of the nasal cavity, via the GSPN and pterygopalatine ganglion, and the submandibular and sublingual glands via the chorda tympani, tonsillar fossae and palate via the GSPN.
_____ fibers for taste innervate the ant 2/3rds of the tongue via the chorda tympani and tonsillar fossae and palate via the GSPN.
Special sensory fibers for taste innervate the ant 2/3rds of the tongue via the chorda tympani and tonsillar fossae and palate via the GSPN.
Special sensory fibers for taste innervate the ant 2/3rds of the tongue via the _____ and tonsillar fossae and palate via the GSPN.
Special sensory fibers for taste innervate the ant 2/3rds of the tongue via the chorda tympani and tonsillar fossae and palate via the GSPN.
_____ fibers provide sensation to touch of the EAC, conchal skin of the auricle, and proprioceptive info from the facial m.
Somatic sensory fibers provide sensation to touch of the EAC, conchal skin of the auricle, and proprioceptive info from the facial m.
The facial nerve traverses the temporal bone w/in a bony canal known as the _____ which begins at the fundus of the IAC and terminates at the stylomastoid foramen.
The facial nerve traverses the temporal bone w/in a bony canal known as the Fallopian Canal which begins at the fundus of the IAC and terminates at the stylomastoid foramen.
Within the IAC, the FN lacks a fibrous sheath or endometrium and is surrounded only by _____,
Within the IAC, the FN lacks a fibrous sheath or endometrium and is surrounded only by a thin layer of arachnoid.
The _____ segment of the FN is the 1st, shortest, and narrowest segment of the fallopian canal.
The labyrinthine segment is the 1st, shortest, and narrowest segment of the fallopian canal.
From the labyrinthine segment, the FN travels ___ to the cochlea and opens into the ___ fossa, located just deep to the STR.
From the labyrinthine segment, the FN travels superior to the cochlea and opens into the geniculate fossa, located just deep to the STR.
The geniculate ganglion is separated from the middle fossa by only a very thin layer of bone, which is dehiscent in ~___% of ears.
The geniculate ganglion is separated from the middle fossa by only a very thin layer of bone, which is dehiscent in ~25% of ears.
The FN acquires a fibrous sheath at and distal to the _____; this is also the location of the facial hiatus, where the GSPN projects anteriorly along the middle fossa floor and of the first genu.
The FN acquires a fibrous sheath at and distal to the Geniculate Ganglion; this is also the location of the facial hiatus, where the GSPN projects anteriorly along the middle fossa floor and of the first genu.
The FN acquires a fibrous sheath at and distal to the Geniculate Ganglion; this is also the location of the _____, where the GSPN projects anteriorly along the middle fossa floor and of the first genu.
The FN acquires a fibrous sheath at and distal to the Geniculate Ganglion; this is also the location of the facial hiatus, where the GSPN projects anteriorly along the middle fossa floor and of the first genu.
At the _____ (where the stapedial tendon emerges), the FN makes a second genu into the mastoid/vertical segment.
At the pyramidal eminence (where the stapedial tendon emerges), the FN makes a second genu into the mastoid/vertical segment.
The _____ of the FN is positioned just anteroinferior to the lateral SCC, and ant to a line drawn through the short process of the incus.
The second genu of the FN is positioned just anteroinferior to the lateral SCC, and ant to a line drawn through the short process of the incus.
The second genu of the FN is positioned just anteroinferior to the _____, and anterior to a line drawn through the _____.
The second genu of the FN is positioned just anteroinferior to the lateral SCC, and ant to a line drawn through the short process of the incus.
The space btwn the _____ of the FN and _____ provide a space through which a posterior Tympanostomy, or Facial Recess can be surgically created to access the middle ear.
The space btwn the mastoid segment of the FN and chorda tympani provide a space through which a posterior Tympanostomy, or Facial Recess can be surgically created to access the middle ear.
The distal aspect of the vertical segment of the fallopian canal and stylomastoid foramen are lined by the aponeurosis of the _____ muscle.
The distal aspect of the vertical segment of the fallopian canal and stylomastoid foramen are lined by the aponeurosis of the posterior belly of the digastric muscle.
The narrow meatal foramen and labyrinthine segment of the FN, is made vulnerable by being a watershed area between terminal arterioles of the ___ and ___ systems.
The narrow meatal foramen and labyrinthine segment of the FN, is made vulnerable by being a watershed area between terminal arterioles of the vertebrobasilar and ECA systems.
The labyrinthine segment is made further vulnerable by the lack of ___ and associated ___, which serves as a barrier to injury and provides a rich collateral blood supply.
The labyrinthine segment is made further vulnerable by the lack of epineurium and associated vascular plexus, which serves as a barrier to injury and provides a rich collateral blood supply.
The geniculate ganglion is susceptible to injury for 3 reasons:
1) _____
2) ganglion is susceptible to injury from pathology or surgical dissection w/in the STR
3) GSPN projects anteriorly, tethering the FN at the hiatus and may exert intraneural traction and shearing forces during temporal bone trauma
The geniculate ganglion is susceptible to injury for 3 reasons:
1) thin and sometimes dehiscent bone that surrounds it makes it vulnerable if temporal bone fractures
2) ganglion is susceptible to injury from pathology or surgical dissection w/in the STR
3) GSPN projects anteriorly, tethering the FN at the hiatus and may exert intraneural traction and shearing forces during temporal bone trauma
The ___ segment of the FN is the most common site of Congenital dehiscence of the bony canal, especially above the oval window.
The tympanic segment of the FN is the most common site of Congenital dehiscence of the bony canal, especially above the oval window.
The _____ segment of FN has the most variable path, especially in associate in w/congenital malformations such as canal atresia.
The vertical segment of FN has the most variable path, especially in associate in w/congenital malformations such as canal atresia.
The FN courses lateral to the _____ as it approaches the stylomastoid foramen and can be injured in transcanal procedures.
The FN courses lateral to the tympanic annulus as it approaches the stylomastoid foramen and can be injured in transcanal procedures.
