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291 Cards in this Set
- Front
- Back
|
what bounds the vestibule of the oral cavity?
|
lips
cheeks |
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what type of epithelium lines the vestibule of the oral cavity?
|
non-keratinized stratified squamous epithelium
|
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where is the parotid papilla?
|
in the superior vestibule, opposite the second upper molar tooth
|
|
|
what is the parotid papilla?
|
projection at the opening of the parotid duct
|
|
|
what supplies blood to the vestibule of the oral cavity?
|
superior labial artery
inferior labial artery |
|
|
how can one control bleeding from the lip?
|
grasp lip between fingers
|
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|
what innervates the orbicularis oris?
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Facial nerve (CN VII)
|
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what innervates the buccinator muscle?
|
facial nerve (CN VII)
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what innervates the skin and mucosa of the upper lip, cheek and vestibule?
|
anterior superior alveolar nerve
middle superior alveolar nerve posterior superior alveolar nerve (all branches from the maxillary division of the trigeminal nerve - V2) |
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from where does the anterior superior alveolar nerve branch?
|
maxillary division of the trigeminal nerve (V2)
|
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|
from where does the middle superior alveolar nerve branch?
|
maxillary division of the trigeminal nerve (V2)
|
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|
from where does the posterior superior alveolar nerve branch?
|
maxillary division of the trigeminal nerve (V2)
|
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what innervates the skin and mucosa of the lower lip and adjacent anterior vestibule?
|
mental nerve
(from mandibular division of trigeminal nerve - V3) |
|
|
from what nerve does the mental nerve branch?
|
mandibular division of trigeminal nerve (V3)
|
|
|
what innervates the mucosa of the inferior vestibule adjacent to the cheek?
|
long buccal (buccinator) nerve
(from anterior division of mandibular division of trigeminal nerve - V3) |
|
|
from where does the long buccal (buccinator) nerve branch?
|
anterior division of mandibular division of trigeminal nerve
(V3) |
|
|
what forms the roof of the oral cavity?
|
hard palate
soft palate midline uvula |
|
|
what forms the posterior border of the oral cavity?
|
pillars of the fauces
|
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what forms the floor of the oral cavity?
|
tongue
|
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what divides the tongue into the anterior 2/3 and the posterior 1/3?
|
palatoglossal arch
sulcus terminalis circumvallate papillae |
|
|
where are the circumvallate papillae?
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lying anterior to sulcus terminalis of tongue
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what is the lingual frenulum?
|
a small fold of mucous membrane extending from the floor of the mouth to the midline of the underside of the tongue
|
|
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where are the openings for the ducts of the submandibular gland?
|
lingual frenulum
|
|
|
what is the common site for cancer of the tongue?
|
lateral aspects of anterior 2/3 of tongue
|
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|
how should one examine a patient's tongue?
|
grasp the tip with gauze
pull the tongue out of the mouth examine lateral aspects of anterior 2/3 |
|
|
what is the plica sublingualis?
|
the posterolateral continuations of the lingual frenulum
|
|
|
where is the sublingual gland?
|
lingual aspect of body of mandible
deep to plica sublingualis |
|
|
how many ducts from the sublingual gland empty into the floor of the mouth on the plica sublingualis?
|
"middle-teens"
15 or 16 |
|
|
where do the ducts from the sublingual gland empty?
|
into the floor of the mouth
on the plica sublingualis |
|
|
what structures lie on the medial surface of the sublingual gland?
|
submandibular gland
lingual nerve |
|
|
what is another name for the submandibular gland?
|
submaxillary gland
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where does the mylohyoid muscle lie in relation to the sublingual gland?
|
inferior to the sublingual gland
|
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what nerve carries postganglionic parasympathetic fibers to the sublingual gland?
|
lingual nerve
(from mandibular division of trigeminal nerve - V3) |
|
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what nerve carries preganglionic parasympathetic fibers, that will synapse with fibers to the sublingual gland?
|
chorda tympani
(facial nerve - CN VII) |
|
|
where do the parasympathetic fibers of the sublingual gland synapse?
|
submandibular ganglion
|
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what provides general sensory innervation of the anterior 2/3 of the tongue and the floor of the mouth?
|
lingual nerve
|
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what is included in the general sensory modality?
|
pain
touch temperature |
|
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what carries special taste fibers and secretomotor fibers of CN VII?
|
chorda tympani
(which is carried by the lingual nerve) |
|
|
where does the lingual nerve enter the mouth?
|
enters the floor of the mouth on the medial aspect of the mandible, next to the third molar tooth
|
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|
during what operation is the lingual nerve vulnerable?
|
extraction of wisdom teeth
|
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what is the path of the parasympathetic fibers to the sublingual gland?
|
preganglionic parasympathetic fibers are carried by the lingual nerve until they synapse in the submandibular ganglion, after which they rejoin the lingual nerve and are finally carried to the sublingual gland
|
|
|
from what is the submandibular ganglion suspended?
|
from the main trunk of the lingual nerve
|
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what is the relationship of the lingual nerve to the mylohyoid muscle?
|
superior to the mylohyoid muscle
|
|
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what is the relationship of the lingual nerve to the submandibular duct?
|
lateral to the submandibular duct in the floor of the mouth, and then subsequently passes inferior and then medial to the submandibular duct to ascend into the body of the tongue
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|
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what is the relationship of the lingual nerve to the sublingual gland?
|
medial to the sublingual gland
|
|
|
what provides taste fibers to supply the anterior 2/3 of the tongue?
|
chorda tympani
|
|
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where are the cell bodies for the postganglionic taste fibers of the anterior 2/3 of the tongue?
|
geniculate ganglion in the middle ear
|
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where is the geniculate ganglion?
|
in the middle ear
|
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|
where does the hypoglossal nerve enter the floor of the mouth?
|
on the lateral aspect of the hyoglossus muscle, above the hyoid bone and above the mylohyoid muscle
|
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|
what is the relationship of the hypoglossal nerve to the lingual nerve?
|
inferior to the lingual nerve
|
|
|
what type of innervation comes from the hypoglossal nerve?
|
motor innervation to muscles of tongue
(except palatoglossus muscle) |
|
|
how can one test cranial nerve XII?
|
hypoglossal nerve
protrusion of the tongue (deviation is toward side of lesion) |
|
|
from what is the anterior 2/3 of the tongue derived?
|
ectodermal stomodeum
|
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from what is the posterior 1/3 of the tongue derived?
|
endodermal foregut
|
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what is another name for the anterior 2/3 of the tongue?
|
body of tongue
oral part of tongue |
|
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what is another name for the posterior 1/3 of the tongue?
|
root of the tongue
pharyngeal part of the tongue |
|
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what separates the ectodermal stomodeum from the endodermal foregut?
|
sulcus terminalis posterior to the circumvallate papillae
|
|
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what can be found at the posterior tip of the V-shaped sulcus terminalis (oriented posteriorly)?
|
foramen cecum
|
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what is the point of origin of the thyroid gland?
|
foramen cecum
|
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where are lingual tonsils located?
|
posterior to the sulcus terminalis
|
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|
what innervates the papillae of the anterior 2/3 of the tongue?
|
cranial nerve VII via chorda tympani
(facial nerve) |
|
|
what innervates the papillae of the posterior 1/3 of the tongue?
|
CN IX (glossopharyngeal nerve)
|
|
|
what are the types of papillae of the tongue?
|
filiform
fungiform circumvallate foliate |
|
|
what innervates the taste buds in the epiglottis and pharyngeal walls?
|
vagus nerve
(CN X) |
|
|
what innervates the taste buds in the palate?
|
facial nerve (CN VII) via the greater petrosal nerve
|
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what distributes the branches from the greater petrosal nerve?
|
greater palatine nerve
lesser palatine nerve |
|
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what is the function of the three extrinsic muscles of the tongue?
|
change position of the tongue
|
|
|
what are the three extrinsic muscles of the tongue?
|
genioglossus
hyoglossus styloglossus |
|
|
what are the attachments of the genioglossus?
|
superior genial tubercles
dorsum of tongue body of hyoid |
|
|
what is the function of the genioglossus?
|
protrudes the tongue
|
|
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what are the attachments of the hyoglossus?
|
hyoid bone (body and greater cornu)
side of tongue |
|
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what is the function of the hyoglossus?
|
depresses the tongue
|
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what are the attachments of the styloglossus?
|
styloid process
tip and sides of tongue |
|
|
on what bone is the styloid process located?
|
temporal bone
|
|
|
what is the function of the styloglossus?
|
retracts the tongue
(bring up sides of tongue to create a trough for swallowing) |
|
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what are the functions of the intrinsic muscles of the tongue?
|
change the shape of the tongue
longitudinal - shorten tongue transverse - narrow & elongate tongue vertical - flatten & widen tongue |
|
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what are the intrinsic muscles of the tongue?
|
longitudinal (superior and inferior)
transverse vertical |
|
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from what artery does the lingual artery branch?
|
external carotid artery
|
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|
what is supplied by the lingual artery?
|
tongue
genioglossus muscle sublingual gland |
|
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what is the only major structure medial to the hyoglossus muscle?
|
lingual artery
|
|
|
what intervenes between CN XII and the lingual artery? how?
|
hyoglossus muscle
CN XII is lateral to it lingual artery is medial to it |
|
|
on what does the lingual artery travel anteriorly in the neck?
|
middle constrictor
(parallel with CN XII) |
|
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what artery supplies the dorsum of the tongue?
|
dorsal lingual artery
|
|
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what artery supplies the body of the tongue?
|
deep lingual artery
|
|
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where do lymphatic of the tongue drain?
|
follow arteries and drain into both right and left jugular lymphatic trunks of the neck
|
|
|
how many teeth are in each adult jaw?
|
4 incisors
2 canines 4 premolars 6 molars 16 in each, 32 total |
|
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what innervates the teeth and gums of the maxillary arch?
|
maxillary division of trigeminal nerve (V2)
molar teeth - posterior superior alveolar nerve premolars - middle superior alveolar nerve canines - anterior superior alveolar nerve incisors - anterior superior alveolar nerve |
|
|
what is another name for premolar teeth?
|
bicuspids
|
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from what nerve does the middle superior alveolar nerve branch?
|
infraorbital nerve
|
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where does the posterior superior alveolar nerve arise from the maxillary division of the trigeminal nerve?
|
pterygopalatine fossa
|
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what innervates the canines and incisors of the maxillary arch?
|
anterior superior alveolar nerve
(from infraorbital nerve) |
|
|
from where does the anterior superior alveolar nerve branch?
|
infraorbital nerve
|
|
|
what nerves innervate the gums on the palatal surface?
|
nasopalatine nerve - incisors
greater palatine nerve - bicuspids and molars |
|
|
what innervates the molar teeth of the maxillary arch?
|
posterior superior alveolar nerve
|
|
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what innervates the bicuspids (premolars) of the maxillary arch?
|
middle superior alveolar nerve
|
|
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what innervates the teeth and gums of the mandibular arch?
|
mandibular division of trigeminal nerve (V3)
|
|
|
what innervates all of the teeth in the mandible?
|
inferior alveolar (dental) nerve
(from V3) |
|
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what innervates the gums of the molars of the mandible?
|
long buccal nerve
(from V3) |
|
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what innervates the gums of the incisors of the mandible?
|
mental nerve
(from V3) |
|
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what innervates the lingual gums of the mandible?
|
lingual nerve
(from V3) |
|
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from where does the nasopalatine nerve branch?
|
maxillary nerve
|
|
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from where does the greater palatine nerve originate?
|
pterygopalatine ganglion
|
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what is the organ of vocalization?
|
larynx
|
|
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at what spinal levels are the upper and lower borders of the larynx?
|
between C4 and C6
|
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at what levels is the cricoid cartilage?
|
C6
|
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what attaches the anterior arch of the cricoid cartilage to the thyroid cartilage?
|
cricothyroid membrane
|
|
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what is the cricothyroid ligament?
|
thickened midline portion of cricothyroid membrane
|
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what forms the laryngeal prominence (adam's apple) after puberty?
|
fusion in midline of right and left laminae of thyroid cartilage
|
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what muscles attach to the oblique lines of the upper and lower horns of each lamina of the thyroid cartilage?
|
sternothyroid
thyrohyoid inferior constrictor muscle |
|
|
to what is the upper edge of the cricoid cartilage attached?
|
thyroid cartilage
|
|
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to what is the upper border of the thyroid cartilage attached?
|
hyoid bone
|
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what attaches the upper border of the thyroid cartilage to the hyoid bone?
|
thyrohyoid membrane
|
|
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what structures pierce the thyrohyoid membrane?
|
internal laryngeal nerve (CN X)
superior laryngeal artery (from superior thyroid artery) |
|
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with what do the inferior horns of the thyroid cartilage articulate?
|
cricoid cartilage
|
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what are the attachments of the cricothyroid muscle?
|
upper border of cricoid cartilage
lower border of thyroid lamina inferior horn of thyroid cartilage |
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what is the action of the cricothyroid muscle?
|
tilts the thyroid cartilage, resulting in tension of the vocal cords
|
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what innervates the cricothyroid muscle?
|
external laryngeal nerve
(from superior laryngeal nerve from CN X) |
|
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where are the arytenoid cartilages?
|
sit on the top of the cricoid lamina
|
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what is the rima glottis?
|
the opening between the vocal cords
|
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what attaches the arytenoid cartilages to the vocal ligament?
|
anterior vocal process
|
|
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muscles of the larynx attach to the lateral muscular processes of what?
|
arytenoid cartilages
|
|
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to what does the apex of the arytenoid cartilages attach?
|
aryepiglottic folds
|
|
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what attaches the apex of the arytenoid cartilages to the aryepiglottic folds?
|
small extensions formed by the corniculate cartilage
|
|
|
if present, where would a cuneiform cartilage be found?
|
aryepiglottic folds, anterior to the arytenoid cartilage
|
|
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what are the attachments of the vocal ligaments?
|
vocal processes of arytenoid cartilages
thyroid cartilage, behind fusion angle |
|
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what are the vocal ligaments actually?
|
superior border of cricothyroid membrane (conus elasticus)
|
|
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where is the stem of the epiglottis attached?
|
above the angle of fusion of the thyroid cartilage
|
|
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what attaches the stem of the epiglottis to the thyroid cartilage?
|
thyroepiglottic ligament
|
|
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what are the attachments of the quadrangular membrane?
|
anteriorly - lateral borders of epiglottis
posteriorly - arytenoid cartilages |
|
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what is the aryepiglottic ligament?
|
free superior border of the quadrangular membrane
|
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what is the vestibular ligament?
|
free inferior border of the quadrangular membrane
|
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what innervates the intrinsic muscles of the larynx?
|
recurrent laryngeal nerves (CN X)
|
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where are the intrinsic muscles of the larynx located?
|
posterior and lateral aspects of the larynx
|
|
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what are the two posterior intrinsic laryngeal muscles?
|
posterior cricoarytenoid muscle
arytenoideus muscle |
|
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what are the attachments of the posterior cricoarytenoid muscles?
|
posterior surface of lamina of cricoid cartilage
posterior aspect of muscular process of arytenoid cartilage |
|
|
what is the only intrinsic laryngeal muscle which opens the rima glottidis?
|
posterior cricoarytenoid muscle
|
|
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what are the actions of the posterior cricoarytenoid muscle?
|
THE abductor of the vocal cords
opens rima glottidis during respiration |
|
|
what could be required if posterior cricoarytenoids are bilaterally paralyzed?
|
tracheostomy
(this is a respiratory emergency caused by injury to recurrent laryngeal nerves) |
|
|
what are the attachments of the arytenoideus muscle?
|
posterior aspects of 2 arytenoid cartilages
|
|
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what are the actions of the arytenoideus muscle?
|
adducts the arytenoid cartilages, vocal processes and vocal cords
|
|
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what forms the aryepiglotticus in the aryepiglottic fold?
|
some fibers of the arytenoideus muscle
|
|
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what are the attachments of the lateral cricoarytenoideus muscles?
|
superior aspect of the arch of the cricoid
anterior surface of the muscular process of the arytenoid cartilage |
|
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what are the attachments of the thyroarytenoideus muscle?
|
internal surface of the angle of the thyroid cartilage
lateral aspect of arytenoid cartilage |
|
|
what forms the vocalis muscle?
|
portion of thyroarytenoideus muscle adjacent to the vocal ligament
|
|
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where does the aryepiglotticus lie?
|
superior border of quadrangular ligament in aryepiglottic fold
|
|
|
where does the thyroepiglotticus lie?
|
medial surface of quadrangular ligament
|
|
|
what are the functions of the posterior cricoarytenoid muscle in respiration?
|
horizontal fibers - abduct vocal processes, open rima glottidis
vertical fibers - pull arytenoid cartilages laterally to further open rima glottidis |
|
|
how are vocal sounds produced?
|
vocal cords are adducted
|
|
|
what is caused by a paralysis of one of the posterior cricoarytenoids?
|
whisper to the voice quality
|
|
|
what affects tension of the vocal cords?
|
vocalis muscle
cricothyroid muscle |
|
|
what happens to the vocal cords in increasing intraabdominal pressure?
|
they are adducted
|
|
|
what happens to the vocal cords in coughing reflex?
|
adduction of vocal cords
increases force of expiration and removes stimulus |
|
|
what laryngeal muscles are involved in swallowing?
|
aryepiglottic muscles
thyroarytenoid muscles thyroepiglottic muscles |
|
|
what actions of the intrinsic laryngeal muscles are involved in swallowing? (by the aryepiglottic muscles, thyroarytenoid muscles, thyroepiglottic muscles)
|
close vestibule
tilt arytenoid cartilages anteriorly assist in depressing epiglottis as the larynx is elevated during swallowing closes superior laryngeal aperture and diverts swallowed food to piriform recesses |
|
|
where is the vestibule of the supraglottic cavity?
|
between the aryepiglottic folds and vestibular folds
|
|
|
where are the ventricles of the supraglottic cavity?
|
between the true and false vocal cords
|
|
|
what provides the sensory innervation to the supraglottic cavity?
|
internal laryngeal nerve
|
|
|
where is the transition from stratified squamous epithelium to ciliated pseudostratified columnar epithelium? why is it clinically important?
|
at the level of the vocal cords
it is a common site of cancer |
|
|
where is the infraglottic cavity?
|
inferior to the vocal cords
continuous with the trachea |
|
|
what provides sensory innervation to the infraglottic cavity?
|
recurrent laryngeal nerves
|
|
|
which nerves are mixed-motor to all laryngeal muscles except the cricothyroid muscle?
|
recurrent laryngeal nerves
|
|
|
what arteries supply the larynx?
|
laryngeal branches of the superior and inferior thyroid arteries
|
|
|
what nerve accompanies the laryngeal branches of the superior thyroid arteries?
|
internal laryngeal nerves
|
|
|
what nerve accompanies the laryngeal branches of the inferior thyroid arteries?
|
recurrent laryngeal nerves
|
|
|
what is the auricle made from?
|
elastic cartilage
(continuous with cartilage of external acoustic meatus and lobule) |
|
|
what is the lobule of the ear made from?
|
loose connective tissue
|
|
|
what are the parts of the external ear?
|
external acoustic meatus
auricle lobule |
|
|
what innervates the superior portion of the external ear (auricle)?
|
auriculotemporal nerve
(mandibular division of trigeminal nerve - V3) |
|
|
what innervates the inferior portion of the external ear?
|
great auricular nerve
(from cervical plexus - C2, C3) |
|
|
what provides the general sensory innervation of the external acoustic meatus and the skin surrounding the opening?
|
vagus nerve (CN X)
|
|
|
what innervates the lobule of the external ear?
|
great auricular nerve
(from cervical plexus - C2, C3) |
|
|
what innervates the posterior part of the external ear?
|
lesser occipital nerve
|
|
|
on examination of the ear, one can determine the neurological status of what?
|
upper spinal cord (C2, C3)
medulla (CN X) pons (CN V) |
|
|
where is the external acoustic meatus?
|
from the concha to the tympanic membrane
|
|
|
which part of the external acoustic meatus is bony? which is cartilagenous?
|
medial 2/3 is bony
lateral 1/3 is cartilagenous |
|
|
what lines the lateral cartilagenous 1/3 of the external acoustic meatus?
|
hair
sebaceous glands ceruminous glands |
|
|
what lines the medial bony 2/3 of the external acoustic meatus?
|
thin stratified squamous epithelium
|
|
|
what lines the external surface of the tympanic membrane?
|
thin stratified squamous epithelium
|
|
|
what provides sensory innervation to the external acoustic meatus?
|
vagus nerve (CN X)
|
|
|
how does the amplification system of the middle ear work?
|
sound waves create vibrations on tympanic membrane
tympanic membrane moves 3 bony ossicles bony ossicles vibrate fenestra vestibuli |
|
|
what are the three bony ossicles of the middle ear?
|
malleus
incus stapes |
|
|
what is the fenestra vestibuli?
|
oval window on the medial wall of the middle ear
|
|
|
what is the middle ear?
|
modified bony sinus in the petrous temporal bone
|
|
|
through what does the middle ear communicate with the mastoid air cells?
|
aditus
|
|
|
through what does the middle ear communicate with the nasopharynx?
|
auditory (eustachian) tube
|
|
|
what is another name for the middle ear?
|
tympanic cavity
|
|
|
what separates the middle cranial fossa from the middle ear?
|
thin layer of petrous temporal bone
|
|
|
what is the epitympanic recess?
|
the space below the roof of the tympanic cavity that houses the head of the malleus and the body of the incus
|
|
|
what does the floor of the tympanic cavity rest on?
|
superior jugular bulb
|
|
|
what is the superior jugular bulb?
|
where the internal carotid artery (moving anteriorly) diverges from the internal jugular vein (moving posteriorly)
|
|
|
what cranial nerves send branches to the bony tympanic floor?
|
glossopharyngeal nerve (CN IX)
vagus nerve (CN X) |
|
|
what divides the auditory tube into a superior compartment and an inferior compartment?
|
processus cochlearis
|
|
|
what is contained in the superior compartment of the auditory tube?
|
tensor tympani muscle
|
|
|
to what does the tensor tympani muscle attach?
|
handle of the malleus
|
|
|
with what does the lower compartment of the auditory tube join?
|
cartilaginous portion of auditory tube
|
|
|
what closes the lateral wall of the tympanic cavity?
|
tympanic membrane
|
|
|
what structure is associated with the anterior tympanic wall?
|
ascending carotid artery
(separated from the tympanic cavity by a thin layer of bone) |
|
|
from what do some patients hear pulsations in some disorders?
|
ascending carotid artery
|
|
|
what is the aditus?
|
tunnel in the posterior wall of the tympanic cavity connecting to the mastoid antrum, which drains fluid from the mastoid air cells
|
|
|
how does fluid drain from the mastoid air cells?
|
drains into tympanic cavity through the aditus, and from there to the nasopharynx through the auditory tube
|
|
|
what happens in the middle ear during an upper respiratory airway infection?
|
fluid collects, because the auditory tube becomes obstructed and the fluid (from the mastoid air cells) cannot drain
|
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where does the facial nerve enter the tympanic cavity?
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posterior wall, below the aditus
|
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where does the facial nerve exit the tympanic cavity?
|
stylomastoid foramen
|
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from where does the chorda tympani arise?
|
from the facial nerve in the posterior wall of the middle ear
(then courses over the eardrum along the lateral wall, exits via petrotympanic fissure into the infratemporal fossa) |
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through what does the chorda tympani exit the tympanic cavity (enters the infratemporal fossa)?
|
petrotympanic fissure
|
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where does the chorda tympani go after exiting the tympanic cavity?
|
infratemporal fossa
(via petrotympanic fissure) |
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through what does the tendon of the stapedius pass to insert on the neck of the stapes?
|
orifice in the apex of the pyramid
|
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what are the actions of the stapedius muscle?
|
retracts stapes from oval window
reflexively attenuates loud sound |
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what are the attachments of the stapedius muscle?
|
walls of pyramidal eminence
neck of stapes |
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what innervates the stapedius muscle?
|
facial nerve (CN VII)
|
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what is hyperacusis?
|
sensitivity to loud sounds
|
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why do bell's palsy patients often complain of hyperacusis?
|
facial nerve is injured, so stapedius muscle is paralyzed
(stapedius muscle attenuates loud sounds) |
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what is within the mucosa covering the promontory of the middle ear?
|
tympanic plexus
(CN VII, IX, X) |
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fibers from which cranial nerves make up the tympanic plexus?
|
CN VII
CN IX CN X |
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what passes through the tympanic plexus?
|
sensory fibers to external and middle ear
preganglionic parasympathetic fibers for greater and lesser petrosal nerves |
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what is posterior and superior to the promontory of the tympanic cavity?
|
oval window
canal for the facial nerve prominence of the lateral semicircular canal |
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what is matched by the shape of the oval window?
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footplate of the stapes
|
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what is posterior and inferior to the promontory of the tympanic cavity?
|
round window
(fenestra cochleae) |
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where is the canal of the facial nerve (CN VII)?
|
horizontal and connects the internal auditory meatus to the descending canal of CN VII in the posterior wall
|
|
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in what does the tympanic membrane lie?
|
in a sulcus in the tympanic bone
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how is the tympanic membrane oriented?
|
laterally, anteriorly and inferiorly
"catches sounds from the ground as one advances" |
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what lines the tympanic membrane medially and laterally?
|
medially - mucous membrane (endoderm)
laterally - epidermis (ectoderm) |
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to what is the handle of the malleus attached?
|
tympanic membrane
|
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to what is the lateral process of the malleus attached?
|
superior pars flaccida
|
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what must be avoided in puncturing the eardrum for draining the middle ear?
|
chorda tympani, located just posterior to the pars flaccida
|
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where are the two synovial joints of the bony ossicles?
|
between malleus and incus
between incus and stapes |
|
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what is otosclerosis?
|
abnormal bone growth in the middle ear that causes hearing loss
|
|
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what is affected by otosclerosis?
|
synovial joints between the bony ossicles
|
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what are the parts of the malleus?
|
head
neck (with anterior process) manubrium (with lateral process and inferior tip) |
|
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what part of the malleus is attached to a stabilizing ligament?
|
anterior process of the malleus, off of the neck of the malleus
|
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what part of the incus articulates with the malleus?
|
body of the incus
|
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to what is the short crus of the incus attached?
|
to the posterior wall of the epitympanic recess (via a ligament)
|
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with what does the long crus of the incus articulate?
|
articulates with head of stapes, via lenticular process
vertically oriented and descending into the tympanic cavity |
|
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what are the parts of the stapes?
|
head
neck anterior crus (limb) posterior crus (limb) base (footplate) |
|
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to what is the footplate of the stapes attached?
|
attached to the oval window, by annular ligament
|
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what is the role of the middle ear?
|
transfer sounds from air to fluid (perilymph)
|
|
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how large is the vibratory surface of the eardrum?
|
55 mm-squared
|
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how large is the footplate of the stapes?
|
3.2 mm-squared
|
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what is the hydraulic ratio between the tympanic membrane and footplate of the stapes?
|
17:1
|
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what is the function of the muscles of the ossicles?
|
attenuates sound by decreasing the movement of the ossicles
|
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where is the tensor tympani?
|
in the auditory canal, running around processus cochleariformis to attach to the handle of the malleus
|
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how does contraction of the tensor tympani attenuate loud sounds?
|
tenses the eardrum by pulling it medially
|
|
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what innervates the tensor tympani muscle?
|
a branch of the mandibular branch of the trigeminal nerve (V3) as it exits the foramen ovale
|
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where is the stapedius muscle?
|
in the pyramid of the posterior wall
inserting into neck of stapes |
|
|
what are the actions of the stapedius?
|
pulls foot plate of stapes away from oval window
dampens sound |
|
|
what innervates the stapedius muscle?
|
facial nerve (CN VII)
|
|
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what is the inner ear?
|
bony labyrinth containing a membranous labyrinth
|
|
|
what composes the bony labyrinth of the inner ear?
|
cochlea
vestibule semicircular canals |
|
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what is the cochlea?
|
snail shell consisting of 2.5 turns, which contains perilymph that receive vibrations from the vestibule, and stimulate the hearing receptors of the inner ear
|
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what lies between the cochlea and semicircular canals, communicating with both?
|
vestibule
|
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which part of the inner ear communicates with the tympanic cavity? via what structure?
|
vestibule
via oval window |
|
|
what are the three semicircular canals?
|
anterior (superior)
posterior lateral (horizontal) lie in three planes |
|
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what is the function of the semicircular canals?
|
maintain balance
|
|
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what surrounds the membranous labyrinth of the inner ear?
|
perilymph
|
|
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what are the parts of the membranous labyrinth of the inner ear?
|
cochlear duct
saccule utricle 3 semicircular canal ducts |
|
|
where is the ductus endolymphaticus?
|
passes from saccule and utricle of inner ear, through a canal in the petrous bone, to a fissure lateral to the internal auditory meatus
|
|
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what is the function of the ductus endolymphaticus? how?
|
acts as a safety expansion
endolymphatic sac is extradural |
|
|
how are vibrations carried for hearing?
|
fluid waves from perilymph are communicated to the endolymph of the cochlear duct for hearing
|
|
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how do the semicircular canals detect motion of the head?
|
angular acceleration of the endolymph in the semicircular canals shifts the endolymph in the semicircular ducts and stimulates vestibular receptors in the ampulla of the semicircular canal
|
|
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what stimulates vestibular receptors in the ampulla of the semicircular canal?
|
angular acceleration of the endolymph in the semicircular canals, shifting endolymph in the semicircular ducts
|
|
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what is the utricle?
|
the larger of the two subdivisions of the membranous labyrinth of the inner ear (other being saccule) which detects movements in the sagittal plane
|
|
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what is the saccule?
|
the smaller of the two subdivisions of the membranous labyrinth of the inner ear (other being utricle) which detects movements in the coronal plane
|
|
|
how do the utricle and the saccule detect movements (position) of the head?
|
gravitational forces act on their receptor mechanisms (hair cells and otoliths)
|
|
|
how can the vestibulocochlear nerve (CN VIII) be tested?
|
placing tuning fork against mastoid process
have patient stand with feet together and eyes closed |
|
|
how is a vestibulocochlear nerve test with a tuning fork against the mastoid process interpreted?
|
bony conduction is heard normally if just the eardrum and bony ossicles are impaired
complete deafness if CN VIII is impaired |
|
|
what is Rinne's test?
|
placing tuning fork on mastoid process and then just outside of ear
|
|
|
what is Weber test?
|
place tuning fork equidistant from both ears on the head, forehead and chin
(look for which side patient can hear noise louder) |
|
|
to which side does a patient fall if the vestibular portion of CN VIII is lesioned?
|
patient falls to the side of the lesion
|
|
|
what artery supplies the inner ear?
|
labyrinthine artery
|
|
|
where does the labyrinthine artery enter the inner ear?
|
enters the internal acoustic meatus, with CN VII and VIII
|
|
|
from where does the labyrinthine artery branch?
|
anterior inferior cerebellar artery
(from basilar artery) |
|
|
strokes in what region can affect the labyrinthine artery?
|
vertebral arterial system
|
|
|
what is innervated by the facial nerve?
|
motor to muscles of facial expression
(stylohyoid, posterior belly of digastric, stapedius) taste (via nervus intermedius) preganglionic parasympathetic fibers to salivary gland (except parotid gland) via nervus intermedius |
|
|
what is innervated by the nervus intermedius?
|
taste (special sensory)
preganglionic parasympathetic fibers to all glands of face except parotid |
|
|
with what does the facial nerve travel through the internal auditory meatus?
|
vestibulocochlear nerve (CN VIII)
|
|
|
what nerves pass in the canal above the vestibule of the bony labyrinth of the ear? which lies on top?
|
facial nerve (CN VII)
vestibulocochlear nerve (CN VIII) facial nerve lies on top |
|
|
what forms the genu, with the geniculate ganglion?
|
facial nerve (after bending on the medial wall of the middle ear)
|
|
|
what is the geniculate ganglion?
|
collection of fibers and neurons for facial nerve located in close proximity to the inner ear
|
|
|
through what does the facial nerve exit the skull?
|
facial canal
stylomastoid foramen |
|
|
what synapses in the geniculate ganglion?
|
nothing
|
|
|
where are cell bodies of the taste fibers of the facial nerve located?
|
geniculate ganglion
|
|
|
what is the path of the greater petrosal nerve?
|
branches from geniculate ganglion
pierces anterior wall of tympanic cavity enters middle cranial fossa |
|
|
what fibers are carried by the greater petrosal nerve?
|
taste fibers for palate
secretomotor fibers for glands in roof of oral cavity, nasal cavity, and orbit |
|
|
from what do both the motor branch to stapedius and chorda tympani branch?
|
descending part of facial nerve (CN VII)
|
|
|
where does the chorda tympani run?
|
between handle of malleus and vertical process of incus
exits into infratemporal fossa via petrotympanic fissure |
|
|
what is carried by the chorda tympani?
|
taste fibers from anterior 2/3 of tongue
secretomotor fibers to submandibular ganglion |
|
|
what are the three tests of the facial nerve (CN VII) with unilateral facial muscle paralysis?
|
chorda tympani - loss of taste in anterior 2/3 of tongue
nerve to stapedius - hyperacusis greater petrosal nerve - lack of lacrimation |
|
|
what happens to the eye if the greater petrosal nerve is impaired?
|
dessication of the cornea, ulceration, and blindness
|
|
|
what nerve would carry pain from dessication of the cornea?
|
ophthalmic division of trigeminal nerve (V1)
|
|
|
where does bell's palsy usually affect the branches of the facial nerve?
|
below the stylomastoid foramen
|
|
|
what indicates a lesion in CN VII between the brainstem and the geniculate ganglion?
|
presence of all 3 signs with facial muscle paralysis
loss of taste in anterior 2/3 of tongue hyperacusis lack of lacrimation |
