9. oral cavity and tongue (lecture) Flashcards
What are the boundaries of the oral cavity?
roof: hard and soft palate
floor: tongue
lateral + medial: cheeks
posterior: oropharyngeal isthmus
anterior: oral fissure (anterior to teeth, aperture)
what is the oral vestibule?
space between teeth and cheeks / lips
anything within the mouth anterior to the teeth
what is the oral cavity proper?
from teeth to the ring made by palatopharyngeal arch, uvula, tip of epiglottis
what are the anterior and posterior arches of the oral cavity?
anterior: palatoglossal arch (palate (roof) to tongue)
posterior: palatopharyngeal arch (palate to oropharynx)
(formed by the palatoglossus (anterior) and palatopharyngeus muscles)
what forms the hard palate?
maxilla and palatine bones
palatine is a continuation of the maxilla bone posteriorly
what is the soft palate?
muscular (valve)
function of the soft palate?
tense and elevate the soft palate during swallowing (pass food down oesophagus) - so soft palate is not in the way
what innervates the muscles of the soft palate?
predominantly vagus nerve (pharyngeal branch) CN X
what happens when the pharyngeal branch of the vagus nerve is damaged?
innervates soft palate
so stronger side is UNopposed (towards unaffected side)
uvula TOWARDS UNaffected side
function of the gag reflex?
to prevent choking
when is the gag reflex examined?
as part of the cranial nerve examination
important for assessing brainstem function
what is the afferent limb of the gag reflex?
glossopharyngeal nerve (CN IX, 9) back of tongue / throat, uvula, tonsillar area (sense)
what is the efferent limb of the gag reflex?
VAGUS nerve (CN X) pharyngeal muscles of soft palate (push down action)
name the teeth from the front back
central incisor, lateral incisor,
canine,
first premolar, second premolar,
first molar, second molar, third molar
what is the sensory supply to the lower jaw?
lower jaw + lower lip (mandibular prominence embryology)
inferior alveolar nerve (branch of V3)
how can the inferior alveolar nerve (V3) be damaged?
can lose sensation during mandibular fracture
site of anaesthesia use in dental surgery
what are the extrinsic muscles of the tongue?
genioglossus
hyoglossus
styloglossus
palatoglossus
function of the extrinsic muscles of the tongue?
helps anchor the tongue (to hyoid bone and mandible)
allows the tongue to change position
what are the intrinsic muscles of the tongue?
superior and inferior longitudinal
vertical
transverse
(both sides separated by septum)
function of intrinsic muscles of the tongue?
help tongue to change shape
action based on the direction fibres run
innervation to muscles of the tongue?
all muscles hypoglossal nerve (CN XII)
APART from palatoglossus (CN X)
general and special sensory innervation to the anterior 2/3rd of the tongue?
general: lingual nerve (CN V3)
special sensation: chorda tympani (CN VII) - petrous temporal bone, then middle ear to tongue
general and special sensory innervation to the posterior 1/3rd of the tongue?
glossopharyngeal nerve (CN IX) 9
what innervates the larynx?
internal laryngeal nerve (branch of vagus, CN X)
which side does the uvula deviate towards?
UNaffected side
which side does the tongue deviate towards?
Affected side
