The Oral Cavity and Pharynx Flashcards Preview

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Flashcards in The Oral Cavity and Pharynx Deck (30):

State the organisation of the fauces

- The fauces are arches formed by the palatoglossus, palatopharyngeal muscles and palatine tonsil
- anterior to posterior - palatoglossus arch, palatine tonsil, palatopharyngeal arch


Describe the muscles of the tongue and their innervation

- Has intrinsic muscles which are not attached to bone but alter the shape of the tongue
- 4 paired muscles all innervated by hypoglossal nerve
- 4 extrinsic muscles change position of tongue and anchor it
- Genioglossus, hypoglossus, styloglossus, palatoglossus
- All innervated by hypoglossal nerve except palatoglossus, which is innervated by the vagus nerve


Describe the sensory and special sensory nerves of the tongue

- Anterior 2/3 sensation provided by mandibular branch of trigeminal
- Taste provided by facial nerve
- Posterior 1/3 sensation and taste from glossopharyngeal


Describe the location and drainage of the submandibular gland

Submandibular gland located below the mouth and secrete through Wharton ducts under the tongue medially


Describe the location and drainage of the parotid gland

Parotid gland secretes saliva through the Stensen duct, located within the cheek next to the 2nd pre-molar


Describe the location and drainage of the sublingual gland

Sublingual gland has multiple ducts to release saliva laterally to the submandibular ducts


State possible pathology within the oral cavity

- Salivary gland stones (siololithiasis)
- Tonsilitis
- Peritonsilar abscess


Describe how salivary gland stones present

- Siololithiasis
- Most stones are located in the submandibular glands
- Leads to dehydration and reduced salivary flow
- Symptoms during eating include pain in gland, swelling or infection


Describe how tonsillitis presents

- Inflammation of the palatine tonsils
- Present with fever, sore throat, pain during swelling, bad breath, cervical lymph nodes


Describe how peritonsillar abscesses present

- Abscess of surrounding tissue around palatine tonsils
- Symptoms include severe throat pain, fever, bad breath, drooling, difficulty opening mouth
- Can follow on from tonsillitis or can arise on its own
- Leads to a deviated uvula


Explain how CN XII is tested

- Wasted tongue
- Stock tongue out, and if affected it deviates to side of lesion
- Protrusion of the tongue is through the genioglossus muscle (innervated by CN XII)


Explain how CN IX and CN X are tested

- Absent gag reflex or uvula deviation
- Gag reflex
- Afferent limb - glossopharyngeal nerve which provides sensation to posterior tongue and oropharynx
- Efferent limb - vagus nerve allows contraction of pharyngeal muscles
- Uvula deviation
- Deviation of the uvula to one side implies a motor lesion of the vagus nerve on the opposite side of the uvula deviating towards


Describe the boundaries and contents of the nasopharynx

- Boundaries - base of skull to upper border of soft palate
- Anterior border is the nasal cavity
- Posterior border is C1, C2
- Contains the pharyngeal tonsil - adenoids
- Also contains the opening of Eustachian tube


Describe the boundaries and contents of the oropharynx

- Boundaries - soft palate to epiglottis
- Anterior border - oral cavity
- Posterior - C2, C3
- Contains the palatine tonsils
- The depressed fossa between the palatoglossal and palatopharyngeal arches is where the palatine tonsils lie


Describe the boundaries and contents of the laryngopharynx

- Boundaries - oropharynx to oesophagus or from epiglottis to cricoid cartilage
- Anterior border - larynx
- Posterior border - C4, C5, C6
- Contains the piriform fossa


State the names and action of the longitudinal muscles of the pharynx

- Stylopharyngeus
- Palatopharyngeus
- Salpingopharyngeus
- Elevate pharynx and larynx during swallowing


Stylopharyngeus AI

- Styloid process to posterior border of thyroid cartilage
- Innervated by glossopharyngeal nerve


Palatopharyngeus AI

- Hard palate to posterior border of thyroid cartilage
- Innervated by pharyngeal branch of vagus nerve


Salpingopharyngeus AI

- Cartilaginous part of Eustachian tube and merges with palatopharyngeus
- Swallowing opens Eustachian tube to equilibrate pressure
- Innervated by pharyngeal branch of vagus


State the names, innervation and action of the pharyngeal constrictors

- 3 circular muscles which constrict walls of pharynx when swallowing
- Superior pharyngeal constrictor
- Middle pharyngeal constrictor
- Inferior pharyngeal constrictor
- Has thyropharyngeal and cricopharyngeal part
- All innervated by vagus nerve


Describe the motor and sensory innervation to the pharynx

- Motor - vagus nerve innervates all muscles except stylopharyngeus
- Sensory
- Nasopharynx - maxillary nerve
- Oropharynx - glossopharyngeal nerve
- Laryngopharynx - vagus nerve


Describe the pharyngeal pouch

- Small area of weakness between the two parts of the inferior pharyngeal constrictor
- Pharyngeal mucosa can herniate through the gap, forming a gap that can trap food
- Leads to failure of the UOS to relax - raised pressure in the area
- Abnormal timing of swallowing


Describe enlarged adenoids and its presentation

- May obstruct passage of air from nasal cavity into the nasopharynx
- Pharyngotympanic tube can be blocked - cause middle ear infections such as otitis media with effusion
- Present with mouth breathing and 'nasal tone' when speaking


Describe the oral phase of swallowing including muscles and nerves involved

- Voluntary
- Preparatory phase - making bolus
- Transit phase - bolus compressed against palate and pushed into oropharynx by tongue and soft palate
- Done through muscles of tongue innervated by hypoglossal nerve


Describe the pharyngeal phase of swallowing including muscles and nerves involved

- Involuntary
- Tongue positioned against hard palate - CN XII through intrinsic and extrinsic muscles of the tongue
- Soft palate elevated to seal off nasopharynx - CN X
- Suprahyoid and longitudinal muscles shorten - CN IX, CN X
- Larynx elevated and sealed off by vocal cords
- Pharynx widens and shortens to receive bolus
- Epiglottis closes over larynx
- Bolus moves through pharynx by sequential contraction of constrictors
- Relaxation of UOS


Describe the oesophageal phase of swallowing including muscles and nerves involved

- Involuntary
- Upper striated muscle of oesophagus - CN X
- Lower smooth muscle


Describe the articulations within the TMJ

- TMJ joint formed from the articulation of the mandible and the temporal bone
- Head of the mandible articulates with the articular disk
- Mandibular fossa also articulates with the articular disk
- Articulating surfaces are lined with fibrocartilage


Describe the ligaments present at the TMJ

- Lateral ligament - runs from articular tubercle to mandibular neck
- Prevents posterior dislocation of the joint
- Sphenomandibular ligament - sphenoid spine to mandible
- Stylomandibular ligament - thickening of the parotid fascia


Describe what muscles are involved in the movement at the TMJ

- Protrusion and retraction through upper part of the jaw
- Protrusion - lateral pterygoid
- Retraction - geniohyoid, digastric
- Elevation and depression through lower jaw - opens and closes mouth
- Depression - normally through gravity, but if resistance then digastric, geniohyoid and mylohyoid
- Elevation - temporalis, masseter, medial pterygoid


Outline how dislocation of the TMJ can occur

- Can occur from trauma, yawning or taking a large bite
- Head of the mandible slips out of the mandibular fossa and is pulled anteriorly
- Facial nerve can be damaged