9.2 Oral Cavity, Tongue, Pharynx Flashcards
What forms the lateral walls of the oral cavity?
Buccinators
What forms the roof of the oral cavity?
Hard and soft palate
What forms the floor of the oral cavity?
2 mylohyoid muscles
Tongue
Other soft tissues
Where does the oral cavity begin and end?
Begins anteriorly at oral fissure
Ends posteriorly at the oropharyngeal isthmus
What forms the sides of the oropharyngeal isthmus?
Anterior and posterior pillars of fauces
What forms the anterior and posterior pillars of the fauces?
Anterior = palatoglossus muscles Posterior = palatopharyngeal muscles
What is the function of the pillars of fauces?
Contraction during chewing pulls soft palate down towards tongue
Closes oropharyngeal isthmus to keep food in the oral cavity whilst chewing
What lies between the anterior and posterior pillars of fauces?
The palantine tonsil within the tonsillar fossa
When is the palantine tonsil visible?
Tonsillitis
How is the oral cavity important to the function of the GI tract?
Entry of food
Mastication to produce bolus
Lubrication and partial digestion of food by saliva
What is sialolithiasis?
Salivary duct stones. Causes pain and swelling of the salivary gland affected. Swelling and pain can fluctuate in relation to eating
What gland is most commonly affected in sialolithiasis?
Submandibular gland
What epithelium covers the tongue?
Squamous epithelium
How many muscles make up the tongue?
8
4 intrinsic
4 extrinsic
What is the attachment site of the intrinsic muscles of the tongue?
The extrinsic muscles of the tongue
What are the 4 extrinsic muscles of the tongue?
Palatoglossus
Hyoglossus
Styloglossus
Genioglossus
What structures anchor the tongue?
Hyoid bone and mandible below
Styloid process and soft palate above
How do we test the function of CN XII?
Hypoglossal nerve tested by testing action of genioglossus muscles. Done by protruding tongue in the midline. Derivation of the tongue from the midline of protrusion indicates weak or paralysed genioglossus muscle
What muscle of the tongue is not innervated by CN XII?
Palatoglossus - forms part of the soft palate and tongue, innervated by the vagus nerve CN X
Why does the tongue receive afferent innervation from a number of cranial nerves?
As tongue derived from a number of pharyngeal arches during embryonic development
What nerve carries general sensation from the anterior 2/3rds of the tongue?
Lingual nerve - branch of the mandibular division of the trigeminal nerve
What nerve supplies the special sensory innervation of the anterior 2/3rds of the tongue?
Chorda tympani - branch of the facial nerve CN VII
The parasympathetics to the sublingual and submandibular glands run with what nerves?
The lingual (CN V) and the chorda tympani (CNVII)
What nerve provide special sensory and general sensory innervation to the posterior 1/3rd of the tongue?
Glossopharyngeal nerve (CN IX)
What nerve provides parasympathetics to the parotid gland?
Glossopharyngeal nerve (CN IX)
How is CN X tested?
Vagus nerve tested by asking patient to open their mouth and say ‘Ahhh’
Uvula inspected for deviation to any one side, indicates weakness of the contralateral soft palate.
What cranial nerves does the gag reflex test?
CN X - vagus (efferent)
CN IX - glossopharyngeal (afferent)
What muscle protrudes the tongue?
Genioglossus
What is the pharynx?
A muscular tube that originates at the base of the skull and extends inferiorly to level C6 where it continues as the oesophagus
What are the 3 divisions of the pharynx?
Nasopharynx
Oropharynx
Laryngopharynx
What covers the posterior wall of the pharynx?
Buccopharyngeal fascia, lies next to the prevertebral layer of the deep cervical fascia
Where is the nasopharynx?
Behind the nasal cavity, above the soft palate.
C1 vertebrae lies posteriorly
What is found in the nasopharynx?
Opening of the posterior nasal apertures
Orifice of the pharyngotympanic tube
Pharyngeal tonsils/adenoids
Where is the location of the oropharynx?
Beneath the soft palate to the superior border of the epiglottis.
Vertebral bodies C2 and C3 lie posteriorly
What structures lie in the oropharynx?
Palatine tonsils
Where is the laryngopharynx?
From the epiglottis to the inferior border of the cricoid cartilage. Behind the larynx. Vertebral bodies C4 C5 and C6 lie posteriorly.
What is the piriform fossa?
A small depression in the laryngopharynx on each side of the laryngeal inlet
What forms the walls of the pharynx?
Circular superior, middle and inferior constrictors