The larynx, pharynx and oral cavity Flashcards
What is the proper name for the gums
gingivae
What are the names for the thin attachments at the base of the tongue and under both lips?
Frenulum- lingual frenulum, and inf and sup labial frenulum
Describe the walls of the oral cavity?
Lateral: buccinators
Floor: muscular diaphragm and tongue
Roof: soft and hard palate
Where can the palatine tonsils be found?
In the tonsillar fossa- between the ant and post faucial pillars (aka glossopalatine and pharyngopalatine arches)
What is the oropharyngeal isthmus?
The arch formed by the hard palate above, tongue below and faucial pillars on either side
How is food kept within the oral cavity when chewing?
The palatoglossus and palatopharyngeal muscles contract to close to oropharyngeal isthmus
How many intrinsic muscles of the tongue are there and what innervated them?
4, all innervated by the hypoglossal nerve. None are attached to bone.
Name the 4 extrinsic muscles of the tongue and what innervates them?
Genioglossus, hypoglossus, styloglossus, palatoglossus.
All innervated by hypoglossal nerve except the palatoglossus which is innervated by the vagus nerve.
Which muscle protudes the tongue?
Genioglossus
What is the name for the ducts that the parotid and submandibular ducts secrete into?
Parotid- stensen ducts in cheek
Submandibular- wharton ducts under tongue
Sublingual secretes into multiple ducts posterior to the submanidibular duct
What may cause salivary duct stones, which duct is most commonly affected and how do they present?
Caused by dehydration and reduced salivary flow. Present w/ pain (worse on eating), swelling, infection and dry mouth
How does a peritonsilar abcess/ quinsy present? (4)
- +/- Recent tosilitis
- fever
- bad breath
- drooling
- difficulty opening mouth
- no pus or redness of tonsils, just large
- uvular deviation
Describe the boundaries of the nasophayrnx
- Base of skull to boarder of soft palate
- behind it is C1 and C2
- in front is the oral cavity
Describe the boundaries of the oropharynx
- From soft palate boarder to epiglottis
- Oral cavity in front
- C2 and C3 behind
Describe the boundaries of the laryngopharynx
- Epiglottis to cricoid cartilage
- larynx in front
- C4,5,6 behind
Describe the sensory innervation to the 3 parts of the pharynx
naso= maxillary nerve (CN Vb) Oro= glossopharyngeal (CNIX) Laryngo= vagus
Describe the musculature of the pharynx
- 3x londitudional muscles to elevate the pharynx and larynx on swallowing
- 3x circular muscles (sup, middle and inf) which constrict the walls to move the bolus down on swallowing
Describe the innervation of the musculature of the pharynx
- All constrictor muscles innervated by vagus nerve
- 1 londitutional muscle innervated by the glossopharyngeal nerve (stylopharyngeus)
- The other 2 londituditonal muscles innervated by the vagus nerve
What is kilians dishiscence?
The point of weakness between the 2 bodies of the inferior pharyngeal constrictor muscle
Describe how a pharyngeal pouch (a posteriomedial false diverticulum/ zenkers diverticulum) occurs?
Failure of UOS or abnormal timing of swallowing occurs which leads to high pressure and weakness at kilians dehiscence leads to outpouching.
What may be the symptoms of a pharyngeal pouch?
bad breath, regurgitation of food, chocking on fluids, general difficult swallowing
Give 4 causes of dysphagia
Stroke, progressive neurological disease, dementia, COPD, cancer
Which nerves are involved in the coordination of swallowing?
CN IX- sensory of bolus at soft palate + stylopharyngeus to elevate larynx.
CNX- Motor to pharyngeal elevators and constrictors and upper portion of muscles of oesphagus, also motor to soft palate elevator to seal off nasopharynx
CN XII- motor to tongue to push bolus backwards
CNVc- motor to one muscle which elevates soft palate and on suprahyoid muscle
When are nasogastric tubes used?
Given to pts who cant swallow eg following a stroke
Why does a pt need to swallow to aid entry of a nasogastric tube?
This closes epiglottis to help ensure the tube goes down the oesphagus not the trachea
Why does an xray or aspirate need to be taken after a nasogastric tube is inserted?
To ensure it is in the oephagus, not the lungs, before you start feeding through it.
Why type of cartilage is present at the joint surface of the temporomandibular joint?
Fibrocartilage not hyaline cartilage
Describe the structure of the temporomandibular joint
Mandibular hear articulates with the temporal bone at the mandibular fossa and articular tubuercle, there is a articular disc between the two bones and a joint capsule
Describe the movements of the temporomandibular joints and name the muscles which bring about these actions
- Protrusion= lateral pterygoid
- Retraction= geniohyoid and digastric
- Elevation= temporalis, masseter and medial pterygoid
- Depression= mainly gravity and lateral pterygoid
- side to side- medial and lateral pterygoid
In which direction does the temporomandbular joint tend to dislocate, what is the mechanism of injury and what action are they unable todo?
Anteriorly (not posterior due to lateral ligament and postglenoid tubercle.
Due to blow to side of head, large bites, yawning.
Cannot close mouth.
What nerves can be injured during a traumatic temporomandibualar joint dislocation?
auricualtemporal joint (branch of Vc) and the facial nerve which run neabry
What ligaments are present which stabilise the temporomandibular joint? (3)
- lateral ligament
- sphenomandibular ligament
- stylomanibular ligament
Which fascia is the thyroid gland enveloped within?
The pre- tracheal fascia- this explains why the thyroid also moves up on swallowing
Is the thyroid gland infront of or behind the sternohyoid and sternothyroid muscles?
Behind
Describe the blood supply of the thyroid gland
Upper & anterior portions supplied by the superior thyroid artery (from ext. carotid).
Lower and posterior portions supplied by the inferior thyroid artery (from the thyrcervical trunk)
Some ppl also have a thyroid ima artery directly off the brachiocephalic trunk
Describe the venous drainage of the thyroid gland
sup, mid and inf thyroid veins form a plexus and drain into the IVC and brachiocephalic trunk
Describe the innervation of the thyroid gland
Supplied by sympathetic trunk but hormone release is entirely under endocrine control.
What nerve, which runs under the thyroid gland, is commonly injured in thryoidectomy?
recurrent laryngeal nerve and also external superior laryngeal nerve
What is the name of the paired cartilages in the larynx which moves the vocal cords and has a signet shape?
The arytenoid cartilages
What is the quadrangular membrane?
A membrane down from the sides of the epiglottis to the arytenoid cartilage, marking the boundaries of the entrance to the trachea
Describe the boundaries of the 3 areas of the larynx?
The supraglottis/ vestible= from epiglottis- valse vocal cords.
The glottis= between the true and false vocal cords.
Infraglottis= between true vocal cords and the tracheal rings
What is the name for the recesses either side of the quadrangular membrane?
The piriform fossa/ recesses- the bolus will flow down these fossa and into the oesphagus on swalllowing
What are the false vocal cords?
Thickening of the lower boarder of the quadrangular ligaments, also called the vestibular ligament
What are the true vocal cords?
Thickenings of the upper boarder of the cricothyroid ligament
What do the true vocal cords look like when viewed with a laryngoscope?
Pearly white and inferior to the false vocal cords. Theyre shaped like a triangle (the point is called the rima glottidis), which points forwards.
When and how is a cricothryroidotomy performed?
In emergency situations when the pt has an upper airway obstruction (eg due to aspiration or swollen vocal cords). It is done by cutting through the cricothyroid ligament and inserting a tube for ventilation
What the difference between the epithelium at the vocal cords and the rest of the larynx?
Vocal cords= stratified squamous
Larynx= psuedostratified columnar
Which muscle abducts the vocal cords? What nerve innervates it?
The posterior cricoarytenoid. It is supplied by the recurrent laryngeal nerve (branch of CN X)
What pitch of sound is created when more tension is put on vocal cords?
Higher pitch
Which muscle adjusts the tension on the vocal cords (and so pitch of voice)?
The cricothyroid muscle- by tilting the thyroid cartilage forwards, thus increasing length and tension on the vocal cords.
Which muscle innervates the cricothyroid muscle?
The external branch of the superior laryngeal nerve
When can the external branch of the superior laryngeal nerve be damaged and what would be the result?
Thyroidectomy- causes hoarseness of voice on attempts to create high pitched noises also +/- monotone voice.
What is the function of the internal branch of the superior laryngeal nerve?
Sensory to the supraglottic region
What is the function of the recurrent laryngeal nerve?
Motor to all intrinsic muscle of the larynx except the cricothyroid muscle. Also sensory to the subglottis region.
When can the recurrent laryngeal nerve be damaged? (3)
AA, pancose tumour, thyroidotomy
Why are progressive impingements of the recurrent laryngeal nerve more life threatening than bilateral legions?
Because progressive impingements paralyse the ability to abduct first so you cannot open the cords at all, where as in bilateral legions you still get some, small ability to adduct the cords. Both need cricothyroidotomys though
Which infections may cause a hoarse voice?
Laryngitis, croup and epiglottitis
What is croup?
An infection (usually viral) which causes swelling of the larynx. It cause a hoarse voice and harsh barking cough. It is usually self limiting but may need steroid treatment.
What organisms cause epiglottitis and how severe are these infections?
Steptococcus, there severe and life threatening
What are singers nodes?
Benign growths on vocal cords caused by over use
How may a goitre cause a hoarse voice?
Impinges on one of the laryngeal nerves
Which lymph nodes are most likely to be enlarged in tonsillitis?
The juglo-digastric nodes
After thyroidectomy a pt starts developing cramps, what complication of the surgery are they suffering from?
Hypocalcaemia
Which salivary gland is most likely to develop caniculi?
the submandibular gland
What is the most common early complication of parotidectomy?
facial droop
