Upper GI Flashcards
Tonsillitis
Tonsillectomy (palatine)
Removal of tonsils and fascial sheet
Rich blood supply from tonsils artery or large external palatine vein
Internal carotid is vulnerable - passes laterally
Can also have adenoidectomy or lingual tonsillectomy (rare)
Muscles controlling mouth apeture
Orbicularis oris muscle - basically surrounds the lips - closes and protrudes the lips
Buccinator - facial nerve - between alveolar mandible and maxilla
Where is oral vestibule?
Between teeth and lip
Palate - innervation, borders?
Sensory innervation to the hard palate is provided by the maxillary branch of the trigeminal nerve (CN V) - PALATINE, whilst the soft palate is innervated by the glossopharyngeal nerve (CN IX). Laterally, the soft palate is continuous with the wall of the pharynx and is joined to the tongue and pharynx by the palatoglossal and palatopharyngeal arches. When the mouth is closed, the oral cavity is fully occupied by the tongue.
Number of teeth
Types
Adults - 32
Children 20 deciduous
Incisors - 8
Canines -4
Premolars - 8
Molars - 12 - incl 4 wisdom
Associated between teeth and maxillary sinus. What can this cause?
The roots of the upper premolars, molars, and occasionally the canine teeth have a close relationship with the maxillary sinus; in some cases, they may even protrude into it.
Maxillary sinusitis often presents as toothache
What forms the floor of oral cavity?
Anterior tongue and mylohyoid (hyoid bone to bottom of chin) - when contracting, elevates the hyoid and the tongue.
Discuss tongue - function, blood supply, innervation
Forms the floor of oral cavity
Functions:
- mastication
- helps swallowing
- detects taste.
Blood supply: lingual artery (branch of the external carotid artery).
Innervation:
- Anterior 2/3: general sensation: lingual nerve of the mandibular branch V3 of trigeminal
- Special sensation (taste): chorda tympani of facial
- Posterior 1/3rd: Both general and special sensation: glossopharyngeal.
Openings of submandibular and sublingual salivary glands
Submandibular - one big duct
Sublingual = a lot of smaller ones
Parotid = top
Summarise intrinsic and extrinsic muscles of the tongue
The intrinsic muscles of the tongue, responsible for the fine movements required to create and move food bo- luses around the mouth (and in some people, rolling of the tongue), are all innervated by the hypoglossal nerve. These muscles are found within the tissue bulk of the tongue and do not attach to bone.
The extrinsic muscles of the tongue control larger tongue movements, including protrusion and retraction. These muscles originate outside of the tongue and attach to it. The palatoglossus, which raises the posterior tongue,is innervated by the Vagus nerve, whilst all other extrinsic muscles are supplied by the hypoglossal nerve.
What are the intrinsic muscles of the tongue
4 paired
Superior longitudinal
Vertical
Transverse
Inferior longitudinal
All innervated by CN 12 - hypoglossal
Discuss extrinsic muscles and innervation
Genioglossus (12) from mandibular symphsis to hyphoid and entire length of tongue
Hypoglossus (12) hyoid to side of tongue - depresses and retracts
Styloglossus (12) - styloid temporal bone to side of tongue - retracts and elevates
Palatoglossus (10) - from palatine aponeurosis (inferior palatine bone) and inserts broadly across tongue, elevates posterior tongue - vagus nerve
Look at image
What is the oropharyngeal isthmus? What muscle alters shape?
The isthmus of the fauces or the oropharyngeal isthmus is a part of the oropharynx directly behind the mouth cavity, bounded superiorly by the soft palate, laterally by the palatoglossal arches, and inferiorly by the tongue.
Back of mouth into throat
Palatoglossus contracts - posterior tongue up and soft palate down
Prevents food from going back into mouth and up nose
Discuss fractures of mandible
Patients with bilateral mandibular body fractures are especially at risk for tongue base prolapse – the fracture may cause the fractured symphysis to slide posteriorly towards the oropharynx, along with the tongue attached to it via its anterior insertion, causing oropharyngeal obstruction in the supine patient.This is a medical emergency as the airway is likely to be compromised.
Risk of respiratory obstruction with bilateral fracture
Damage to mandiular branch V3
Discuss salivary glands
- Parotid gland – a lobular, irregular gland located in the parotid region of the face, posterior to the cheeks and anterior to the external ear. Secretions are passed via Stensen’s (parotid) duct, which pierces the buccinator, to drain into the oral cavity adjacent to the second upper molar tooth.The parotid gland is innervated by the parasympathetic fibres of the glossopharyngeal nerve, which pass via the otic ganglion.
- Submandibular gland – flattened glands located in the submandibular triangle of the neck, beneath the floor of the oral cavity. Secretions drain via Wharton’s (submandibular) duct which drains into the oral cavity through 1-3 orifices at the base of the frenulum of the tongue.The submandibular gland is innervated by the parasympathetic fibres of the facial nerve, which pass via the submandibular ganglion. Via chorda tympani
- Sublingual gland – small, oval glands on the floor of the oral cavity, under the tongue. Secretions drain via multiple minor sublingual ducts onto the sublingual folds under the tongue.The sublingual gland is innervated by the parasympathetic fibres of the facial nerve, which pass via the submandibular ganglion. Via chorda tympani
Sialolithiasis
Stones can form in the major salivary glands and their ducts, causing blockage of salivary outflow, particu- larly causing pain and swelling at mealtimes.
Inside salivary glands
Mucus, debris and calcium
Most commonly in submandibular gland and duct
Often found in the papillae of salivary glands - narrowest part
In the parotid - at main confluence of ducts - also common
Most pass spontaneously - pain relief, good hydration and warm compresses.
Which gland is the facial nerve associated with?
Parotid
Passes through and branches
What happens in a tumour of parotid gland
Risk to facial nerve - ipsilateral side of face affected
What vessels pass through the parotid gland/supply the parotid gland?
The external carotid artery and its terminal branches within the gland, namely, the superficial temporal and the maxillary artery, also the posterior auricular artery supply the parotid gland.
Venous return is to the retromandibular veins.
Discuss course of facial artery
Loops over submandibular gland
What are the processes of the mandible? Where are they?
Condylar and coronal process
The condylar = temporomandibular joint
What passes through the mandibule canal? When is it commonly damaged
V3 mandibular branch - inferior alveolar nerve - sensation to the lower teeth
Discuss temporo-mandibular joint
Bicondylar joint
Condylar process with glenoid fossa of the skull
Within each part of the joint, an articular disc separates the joint into upper and lower joint cavities.The upper joint cavity is a sliding joint, allowing the protrusion and retrusion of the mandible.The lower joint cavity primarily acts as a hinge joint, but some rotation is permitted.This is associated with the grinding motion of the teeth during chewing.
Dislocation of the temporo-mandibular joint
Dislocation on over-opening
Need to depress mandible before reduction
TMJ dislocation occurs when the condylar process moves anterior of the articular eminence and fails to return to its normal position.
Dislocation may be caused by forceful wide opening of the mouth whilst yawning, vomiting or undergoing seizures.
The most common symptom are the inability to close the oral cavity, difficulty in speech and drooling saliva.
Acute dislocations may be managed with pain relief and manual reduction, which involves depression of the mandible using the intra-oral technique.
Discuss mastication
Food manipulated by rolling tongue movements - both intrinsic and extrinsic muscles
Food maintained between hard surfaces of the teeth
Buccinators pull cheeks inward to prevent the accumulation of food within oral vestibule
Food retained in mouth by contact between soft palate and tongue
What nerve does muscles of mastication
Movements of the temporomandibular joint are produced by the muscles of mastication, which include tempo- ralis, masseter and the medial and lateral pterygoids.These muscles are all innervated by the mandibular branch of the trigeminal nerve. Depression of the mandible is predominantly produced by gravity.
Functions of muscles of mastication
Innervation of jaw
The inferior alveolar nerve, which is a branch of the mandibular branch of trigeminal (CN V) and innervates the lower teeth, passes through the mandibular canal via the mandibular foramen on the inner aspect of the mandible. Anteriorly, the nerve gives off the mental nerve, which exits the mandible via the mental foramen to supply the skin of the chin and lower lip.
What are the 3 regions of the pharynx? Where do they extend from and to? What tonsils do they contain?
- Nasopharynx – located between the base of the skull and the soft palate.
- The Eustachian tubes drain into the nasopharynx at the level of the inferior nasal concha, equalising pressure across the tympanic membrane.
- The wall of the posterosuperior nasopharynx contains the adenoid tonsils, which are particularly prominent in children.
- Oropharynx – extends between the soft palate and the superior part of the epiglottis.
* Contains the palatine tonsils within the tonsillar fossa and the lingual tonsils at the base of the tongue.The superior pharyngeal constrictor muscle constricts the walls of the oropharynx. - Laryngopharynx – extends from the superior part of the epiglottis to the inferior border of the cricoid cartilage at the level of C6, where it is continuous with the oesophagus.
- It is therefore located posterior to the larynx.
- The middle and inferior pharyngeal constrictors constrict the walls of the laryngopharynx.
- The cricopharyngeus muscle of the laryngopharynx, also called the upper oesophageal sphincter, is tonically contracted at rest, but relaxes to allow the passing of food boluses during the process of swallowing.
What are the two main groups of pharyngeal muscles?
longitudinal and circular.
Discuss circular muscles and innervation
There are three circular pharyngeal constrictor muscles; the superior, middle, and inferior pharyngeal constrictors. They are stacked like glasses, which form an incomplete muscular circle as they attach anteriorly to structures in the neck.
The circular muscles contract sequentially from superior to inferior to constrict the lumen and propel the bolus of food inferiorly into the oesophagus.
Superior pharyngeal constrictor – the uppermost pharyngeal constrictor. It is located in the oropharynx.
Middle pharyngeal constrictor – located in the laryngopharynx.
Inferior pharyngeal constrictor – located in the laryngopharynx. It has two components:
- Superior component (thyropharyngeus) has oblique fibres that attach to the thyroid cartilage.
- Inferior component (cricopharyngeus) has horizontal fibres that attach to the cricoid cartilage.
All pharyngeal constrictors are innervated by the vagus nerve (CN X).
Discuss longitudinal muscles - what do they do?
They act to shorten and widen the pharynx, and elevate the larynx during swallowing.
The longitudinal muscles are the stylopharyngeus, palatopharyngeus and salpingopharyngeus.
In addition to contributing to swallowing, salpingopharyngeus also opens the Eustachian tube to equalise the pressure in the middle ear.
Innervation of pharynx muscles
Sensory
- The pharynx receives sensory innervation from the glossopharyngeal nerve.
- In addition:
- The anterior and superior aspect of the nasopharynx is innervated by the maxillary nerve (CN V2)
- The inferior aspect of the laryngopharynx (surrounding the beginning of the larynx) is innervated by the internal branch of the vagus nerve.
Motor
- All the muscles of the pharynx are innervated by the vagus nerve (CN X), except for the stylopharyngeus, which is innervated by the glossopharyngeal nerve (CN IX).
What is pharynx vasculature?
External carotid - ascending pharyngeal
Venous = pharyngeal venous plexus which drains into internal jugular
What is retropharyngeal space?
Lies just behind pharyngeal space
The retropharyngeal space is more susceptible to infections that originate in Waldeyer’s tonsillar ring that spread to the retropharyngeal lymph nodes. Also, cellulitis on a dental abscess may infect this space which is worrisome because it may pass into the danger space, which is the space that connects the fascial spaces of the head and neck to the superior mediastinum and can carry an infection into the thorax.
Discuss pharyngeal diverticulum
Pharyngeal pouch / diverticulum can form above
cricopharyngeus due to incoordination of the sphincteric action.
Get filled with food
Need to be excised
Discuss chewing and swallowing
The muscles of mastication (temporalis, masseter, medial & lateral pterygoids) facilitate the chewing, cutting and grinding of ingested food into a semi-solid bolus. During the voluntary phase of swallowing, the bolus is compressed against the hard palate by the extrinsic tongue muscles. Simultaneously, a trough is created at the posterior of the tongue by the intrinsic muscles which forces the bolus into the oropharynx.
The next stage is involuntary and rapid: the levator veli palatini (innervated by Vagus) and tensor veli palatini (innervated by mandibular branch of trigeminal) contract to seal off the nasopharynx from the oropharynx.
The pharynx then widens whilst the larynx is elevated by the suprahyoid group of muscles.This closes the larynx by causing the epiglottis to close over its inlet.
Finally, a wave of involuntary contractions of the superior, middle and inferior pharyngeal constrictor muscles (innervated byVagus) forces food into the oesophagus.
Discuss gag reflex and neuropathies
Triggered by mechanical pressure to posterior pharyngeal wall - rapid elevation of soft palate and contraction of pharyngeal muscles
Consensual reflex - if you stimulate the right side, you get a bilateral response
Afferent - glossopharyngeal
Motor = vagus
Glossopharyngeal neuropathy - non gag reflex when touching affected side
Vagus damaged - touchingg the affected side: elevation of the soft palate on the unaffected side, as glossopharyngeal is still in tact
Discuss gag reflex and neuropathies
Triggered by mechanical pressure to posterior pharyngeal wall - rapid elevation of soft palate and contraction of pharyngeal muscles
Consensual reflex - if you stimulate the right side, you get a bilateral response
Afferent - glossopharyngeal
Motor = vagus
Glossopharyngeal neuropathy - non gag reflex when touching affected side
Vagus damaged - touchingg the affected side: elevation of the soft palate on the unaffected side, as glossopharyngeal is still intact
Relationship between parotid and buccinator
How is this clinically relevant?
In all cases, the parotid duct pierced the maxillary portion of the buccinator muscle and entered the oral cavity at the parotid papilla.
The facial nerve and its branches pass through the parotid gland, ultimately supplying motor innervation to the muscles of facial expression, posterior belly of digastric and the stylohyoid muscles. It is therefore critical to have an appreciation of the anatomy of the parotid gland and the facial nerve when operating on the gland. Facial nerve injury and subsequent facial palsy is the most common complication of surgery, which results in an ipsilateral facial droop.The nerve must be carefully identified and dissected out early in surgery before gland resection continues, to avoid these complications. Compressive effects from tumours can also result in a similar palsy.
Muscles of soft palate and innervaiton
All by pharyngeal branch of vagus apart from tensor veli palatini - medial pterygoid nerve (a branch of CN V3).
- Tensor veli palatini - tenses
- Levator veli palatini - elevates soft palate
- Palatoglossus - pulls soft palate towards tongue
- Palatopharygeus - draws pharynx anteriorly
- Musculus uvulae - shortens uvula
Sensory innervation of palate
Maxilary trigeminal
Tonsillitis
Tonsillitis describes inflammation of the tonsils due to infection. Patients complain of sore throat and dif- ficulty swallowing. Most cases of tonsillitis are viral and so should be managed with pain relief, hydration and lozenges.Antibiotics should only be given if the tonsillitis is likely to be bacterial in nature: a lack of cough, pus on the tonsils, fever above 38°C and swol- len neck lymph nodes all increase the likelihood of the infection being bacterial. If tonsillitis becomes a recurrent problem, patients can undergo a surgical excision of the tonsils (tonsillectomy).
