Lecture 18- The oral cavity and the pharynx Flashcards
what separates the nasal cavity from the oral cavity
the hard and soft palate
- Tip of soft palate= uvula
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tip of the soft palate is the
uvula
how many teeth do we have
32
area between the lips and teeth
vestibule
where do the tonsils sit
- Palatoglossal and palatopharyngeal arches (Mc Donalds signs)
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the tongue has
intrinsic and extrinsc muscles
intrinsic muscles of the tongue
- not attached to other muscles except other intrinsic muscles
- 4 pair muscles
- Longitudinal (superior and inferior)
- Transverse
- Vertical
- 4 pair muscles
motor innervation of the itnrinsic muscles
hypoglossal enrve (CN XII)
extrinsic muscles
- arise from other structures and insert into tongue
extrinsic muscles
- Genioglossus
- Hyoglossus
- Styloglossus
- Palatoglossus
Styloglossus
- Motor innervation: hypoglossal nerve
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palatoglossus
- Motor innervation (vagus nerve)
anatomy of the extrinsic muscles
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sensory supply of the tongue (anterior 2/3)
- Sensation- trigeminal (V3)
- Taste- facial
posterior 1/3 of the tongue
- Sensation and tase- glossopharyngeal
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how many pairs of salivary glands
3
salivary glands
- parotid
- submandibular
- sublingual
where does the parotid lie
- Lies anterior to the SCM and ear
- Behind the masseter and zygomatic arch
- Duct opens up in the upper region of the oral cavity- Stenson’s duct (near upper 2nd molar)
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submandibular gland
- Most of saliva (60%)
- Sits under the mandibular in the submandibular triangle
- Saliva exits the Wharton’s ducts
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- Sublingual
- Under the tongue
- Produce 3-5% of saliva
- Smallest and most diffuse of the majority salivary glands
- 8-20 excretory ducts per gland
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Salivary gland stones (sialolithiasis) most commonly found in the
submandibular - whartons ducts
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causes of salivary stones
- Dehydration, reduced salivary flow
- Most stoned less than 1cm
- Symptoms (eating) of sialothiasis
- Pain in gland
- Swelling
- Infection
diagnosis of sialolithiasis
-
Diagnosis
- History
- X-ray
- Sialogram- contrast dye injected into gland
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what is tonsilitis
inflammation of the palatine tonsils
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Symptoms of tonislitis
- Fever
- Sore throat
- Pain/difficulty swallowing
- Cervical lymph nodes
- Bad breath
tonsilitis causes
- Viral causes (most common)
- Bacterial causes (up to 40% of cases)
- Strep pyogenes
- White spots
- Can be bacterial secondary to viral tonisilittis
Peritonsillar abscess
Diff to tonsilitis
- Affects tissue around the tonsil
- If its unilateral (quinsy)à will deviate the uvula towards the swelling
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Symptoms of peritonsilar abscess
- Severe throat pain
- Fever
- Bad breath
- Drooling
- Difficulty opening mouth
when can peritonsillar abscesses occur
Severe throat pain
Fever
Bad breath
Drooling
Difficulty opening mouth
the pharynx can be split in 3
(all exist behind various structures)
-
Nasopharynx
- Behind nasal cavity
-
Oropharynx
- Behind oral cavity
-
Laryngopharynx
- Behind larynx
the nasopharynx is the
upper pharynx- pink part
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where is the nasopharynx found
- Behind the nasal cavity
borders of the nasopharynx
- Base of skull- upper border
- C1,C2- posterior border
- Nasal cavity- anterior border
the nasopharynx contains the
- Pharyngeal tonsil e.g. adenoids
Pharyngeal tonsil (adenoid)- clinical correlates
*
- Enlarged pharyngeal tonsils
- Block eustachian tube (recurrent/persistent middle ear infection
- Snoring/sleep apnoea
- Sleeping with mouth open
- Chronic sinusitis
- Sore throat
- Nasal tone to voice
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the oropharynx- middle pharynx
- Yellow part on photo
- Starts where the nasopharynx end
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borders of the orpharynx
- Soft palate to epiglottis
- Anterior- oral cavity
- Posterior (C2,C3)
oropharynx contains the
palatine tonsils
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coronal view of the pharynx
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the laryngopharynx
lower pharynx
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borders of the laryngopharynx
- Oropharynx to oesophagus
- Epiglottis to cricoid cartilage
- Anterior- larynx
- Posterior (C4, C5, C6)
laryngopharynx contains
- Piriform fossa
piriform fossa
- Epiglottis (flap on right photo) acts as a director of flow of fluid and water into the piriform fossa into the oesophagus instead of the trachea
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General overview of muscle arrangements of the pharynx
3- longitudinal muscles
Stylopharyngeus
Palatopharyngeus
Salpingopharyngeaus
They act to shorten and widen the pharynx, and elevate the larynx during swallowing.
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3 longitudinal muscles
elevate pharynx and larynx during swallowing
- Stylopharyngeus
- Palatopharyngeus
- Salpingopharygeus
Stylopharyngeus
- Originates from the styloid process and goes down to the posterior border of the thyroid cartilage
- Innervation- glossopharyngeal nerve (CN IX)
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Palatopharyngeus
- Originates from the hard palate and extends down to the attach to the posterior border of the thyroid gland
- Pharyngeal branch of vagus (CN X)
Salpingopharyngeaus
- Originates from the cartilaginous part of ET- merges with the palatopharyngeus
- Pharyngeal branch of vagus (CN X)
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pharngeal constrictors
X3 circular (more semi-circular) muscles all insert on the pharyngeal raphe)
- Constrict walls of pharynx when swallowing
what are the 3 circular muscles
-
Superior pharyngeal constrictor
- Origin – pterygomandibular raphe
-
Middle pharyngeal constrictor
- Origin- hyoid bone
-
Inferior
- 2 parts
- Thyropharyngeal (origin- thyroid cartilage)
- Cricopharyngeal (origin- cricoid cartilage
- 2 parts
- All supplies by the vagus nerve
what do pharngeal constrictures and the pharngeal raphe loop like
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Pterygomandibular raphe
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3 forms of innervation of the pharynx
- pharyngeal plexus
- motor
- sensory
- Pharyngeal plexus
- Located mainly on surface of middle constrictor muscle
- Vagus, glossopharyngeal and cervical sympathetic nerve
- Motor
- CNX -Vagus innervates all muscles
- Except stylopharyngeus (glossopharyngeal nerve (CN IX)
- Sensory
- Nasopharynx (maxillary nerve CN V2)
- Oropharynx ( glossopharyngeal nerve CN IX)
- Laryngopharynx (vagus nerve CNX)
Clinical correlates with pharyngeal
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- Caused by a posteromedial (false diverticulum)à arises in weakness between the 2 parts of the inferior constrictor (Killians dehiscence)
false diverticulum in killians dehiscence is probably caused by
- Failure of UOS to relax
- Abnormal timing of swallowing
- Essentially there is a higher pressure in laryngopharynx
- Weakness in inferior constrictor muscle produces outpouching
- Essentially there is a higher pressure in laryngopharynx
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stage sof swallowing
oral
pharngeal
oesophageal
outline the oral stage of swallowing (stage 1)
- voluntary
- prepatory phase- making the bolus
- transit phase- bolus compressed agaisnt palate nad pushed into oropharynx by tongue and soft palate
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which nerve is associated with the oral stage
hypoglossal CNXII- muscles of the tongue
outline the pharyngeal phase of swallowing
- involuntary
- tongue positioned against the hard palate (food cannot re-enter mouth (CN XII)
- soft palate elevated sealing off nasopharnx
- opens ET tubule
- suprahyoud and longituidnal muscles shorten
- pharynx widwns and shortens to receive bolus
- larymx elevated and sealed off by vocal folds
- epiglottis closes over larynx (result of elevated hyoid)
- bolus moves throguh pharynx by sequential contraction of constrictors
- relaxation of the UOS
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pharangeal phase is
dangerous- shared airway sapce
- Need to protect airway
- By shortening longitudinal muscles- elevate larynx and pharynxà widening it
- Closure of epiglottis (sealing the airway)
Oesophageal phase
- involuntary
- uppder strated muscle of oesophagus (CNX)
- lower smooth muscle
- LOS covered in GI unit
dysphagia
problems swallowing
Neurological conditions makes swallowing liquids harder (solid= more due to obstruction)
Signs and symptoms of dysphagia
- Coughing and chocking
- Sialorrhea (drooling)
- Recurrent pneumonia
- Change in voice/speech (wet voice)
- Nasal regurgitation
causess of dysphagia
- Stroke
- Progressive neurological disease
- Parkinson’s/MS
- COPD
- Dementia
- 30% of post stroke death are due to pneumonia
- E.g. aspiration pneumonia
dysphagia interventions
Fluids are thickened
1) cranial nerve problems with dysphagia realted to which CN
Intervention
- Fluids are thickened
- Absent gag
- Uvula deviated away from lesion (Lower Motor Neurone lesion)
- More subtle
- Dysphagia
- Taste impairment (posterior tongue IX)
- Loss of sensation oropharynx
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Injury to IX/V caused by
Medullary infarct, jugular foramen issues (fracture)
2) Cranial nerve problems in this area
*
XII- hypoglossal
- Wasted tongue
- Stick tongue out- tongue may deviated
- Damage to nerve itself (LMN)- points to side of the lesion (tongue never lies)
- Muscle wasting
- Fasciculations
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