Lecture 15 - Oral cavity, tongue and pharynx Flashcards
Borders of the oral cavity
Lateral walls - buccinator
Roof - Hard and soft palate
Floor - mylohyoid muscles and tongue
Archs in oral cavity
palatoglossal arch - anterior
palatopharyngeal - posterior
Lingual frenulum
Connective tissue attachning tongue to base
In base can become tongue tied - snip lingual frenulum if not eating
Vestibule
Lateral border of teeth and lips space
oropharyngeal isthmus
Arch formed by the soft palate and tongue + palatoglossal and palatopharyngeal arches anteriorly and posteriorly
Tongue lining
Squamous epithelium mucous membrane
Intrinsic muscles of the tongue
Motor innervation - hypoglossal nerve
Alter shape of tongue
Extrinsic muscles of the tongue
Motor innervation by hypoglossal nerve:
- Genioglossus - attached to mandible. Protrudes tongue
- Styloglossus - attached to styloid process
- Hypoglossus - attached to hyoid bone
Motor innervation by vagus nerve:
- Palatoglossus - attached to soft palate
Change the position of the tongue:
- retract
- protract
- up and down
- side to side
Anchor tongue to surrounding structures:
- hyoid
- mandible
- soft palate
- styloid process
Innervation to tongue
Posterior 1/3rd:
- General sensory : glossopharyngeal
- Taste: Glossopharyngeal
Anterior 2/3rds
- General sensory: Lingual nerve (Vc)
- Taste - Facial nerve chorda tympani (PS run with lingual nerve)
CN X test
- Say ‘aah’ - uvula inspected for deviation - uvula deviated away from lesion
- Gag reflex
- Tongue deviation - tongue deviates towards side of lesion
CN XII test
Tongue movements
Salivary glands
Saliva lubricates food
Contains salivary amylase and lipase to chemically breakdown food
Contains immunoglobulin for immune defence
Wharton duct
Submandibular duct at the base of the lingual frenulum
Sialoliathiasis
Stones form in the salivary ducts causing:
- pain
- swelling
- fluctuates related to eating
- dehydration
- reduced salivary flow
- infection due to stasis
Submandibular duct most commonly affected (wharton’s)
Stensen duct
Parotid gland duct
Traverses over th masseter and pieces the buccinator near 2nd premolar
Sublingual gland
Smallest salivary gland
8- 20 excretory ducts per gland
How to diagnose sialolithiasis
History
Xray
Sialogram - locates blockage
Tonsilitis presentation
Inflammation of the palatine (visible) tonsils
- fever
- sore throat
- dysphagia and pain
- swollen cervical lymph nodes (jugulodiagastric)
- Bad breath
- exudate on palatine tonsils
- central uvula
Commonly viral cause
Most common cause of tonsilitis
Strep pyogenes (40%)
Peritonsillar abscess (Quinsy) presentation
- Fever
- Bad breath
- Drooling
- Dysphagia
- Deviated uvula
- Difficulty opening mouth
Can occur due to untreated or partially treated tonsilitis or on its own via aerobic or anaerobic bacteria
Epiglottitis
Inflammation of epiglottis - can snap shut if poked and close airway
Nasopharynx boundaries
Base of skull to upper border of the soft palate
C1 - C2
Posterior to the nasal cavity
What does the nasopharynx contain?
Pharyngeal tonsils (adenoids)
Eustachian tube orifice
Lymphoid tissue
Adenoiditis
Enlarged pharyngeal tonsils
Block ET - otitis media +/- effusion
- Snoring
- Sleep with mouth open
- Chronic sinusitis
- Sore throat
- Nasal tone of voice
Prominent in children as the adenoids undergo atrophy during puberty
Oropharynx boundaries
C2 - C3
Soft palate to epiglottis
Posterior to the oral cavity
What does the oropharynx contain?
Palatine tonsils
Palatoglossal and palatopharyngeal arch
Laryngopharynx boundaries
Epiglottis to cricoid cartilage
C4, C5, C6
Posterior to the larynx and trachea
What doe the laryngopharynx contain?
Piriform fossa
Piriform fossa
Small depression either side of the glottis.
Potential site for foreign bodies to lodge and pharyngeal cancer to develop
Longitudinal muscles of the pharynx
Stylopharygeus - styloid process
Palatopharygeus - hard palate
Salpingopharyngeus - cartilaginous ET (merges with palatopharyngeus)
- Elevate the larynx and pharynx during swallowing and speech
- Innervated by the pharyngeal branch of the vagus nerve except the stylopharyngeus
- Shorten and widen the pharynx
- Inserted onto the thyroid cartilage
Stylopharyngeus
Insertion: styloid process
Attachment: thyroid cartilage
Action: Raise pharynx and larynx during swallowing
Innervation: glossopharyngeal nerve
3 circular pharygeal constrictors
- Superior pharyngeal constrictor
- Middle pharyngeal constrictor
- Inferior pharyngeal constrictor:
> thyropharyngeal
> cricopharyngeal - Constrict walls of pharynx when swallowing
- Contract and relax in waves to send food down the oesophagus
- Innervation - vagus nerve
- Insertion - pharygeal raphe
- Covered with buccopharyngeal fascia
Killian’s dehiscense
Area of weakness between the thyropharngeal and cricopharyngeal inferior pharyngeal constrictor.
Uncoordinated swallowing e.g. thryopharyngeus contracts against the cricopharyngeus can cause pharyngeal mucosa to herniate through Killian’s dehiscense to form a diverticulum (pharygeal pouch).
Origins of 3 pharyngeal circular constrictors
Superior pharyngeal constrictor - pterygomandibular raphe
Middle pharygeal constrictor - hyoid bone
Inferior pharyngeal constrictor - thyroid and cricoid cartilage
Pharyngeal pouch presentation
Presents as:
- dysphagia
- asymptomatic
- regurgitation
- lump in neck
- bad breath
Pharyngeal plexus
Located mainly on the middle pharyngeal constrictor
Made up of vagus and glossopharyngeal nerve and cervical sympathetic nerve of the the superior cervical ganglion
Motor innervation
Vagus nerve except glossopharyngeal motor innervation to the stylopharygeus
Sensory innervation
Nasopharynx - CN Vb
Oropharynx - CN IX
Laryngopharnx - CN X
Stages of swallowing
Stage 1 - oral
Stage 2 - pharygeal
Stage 1 of swallowing (oral)
Voluntary
Preparatory phase where the bolus is made and transported into the oropharynx
The bolus is compressed against the palate and pushed into the oropharynx by the tongue and soft palate.
CN XII - muscles of tongue
Stage 2 of swallowing (pharyngeal)
Involuntary
- The tongue is pressed against the hard palate CN XII
- The soft palate is elevated, closing the nasopharynx inlet (tensor palatini CN Vc and levator palatini CN X)
[ET opened] - Suprahyoids (CN Vc, CN VI, CN XII) and longitudinal muscles (CN X, CN IX) shorten which elevate the larynx - sealed off by vocal cords
and the pharynx shortens and widens to allow bolus to enter - Epiglottis closes over the larynx due to elevated hyoid
- Bolus moves through the pharynx via sequential contractions and relaxations of constrictors
- Relaxation of UOS
Stage 3 of swallowing
oesophageal
Involuntary
Upper striated muscle of oesophagus (CN X) and lower smooth muscles
Lower oesophageal sphincter opens
Neurological dysphagia
Vagus, glossopharyngeal or hypoglossal nerve lesion
- Give thickened fluids for better control
Dysphagia presentation
- Difficulty swallowing
- Coughing or choking
- Sialorrhoea - drooling
- Recurrent pneumonia
- Change in voice
- Nasal regurgitation
Vagus nerve lesion causes
Medullary infarct
Jugular foramen issue e.g. fracture
Hypoglossal lesion
Wasted tongue
Tongue deviates to side of lesion
Fasiculations
