Pharynx Flashcards
Where does the pharynx begin and end?
Base of skull
Proximal oesophagus
What forms the anterior, posterior and lower borders of the nasopharynx?
Anterior: choanae
Posterior: Body of C1 vertebra (and superior part of C2)
Lower: Soft palate
When is the nasopharynx closed off from the rest of the pharynx?
What controls this movement?
During swallowing when the soft palate contracts to close the gap.
Controlled by:
-Tensor veli palatini (Stretches soft palate)
-Levator veli palatini (elevates soft palate)
Where does the oropharynx begin and end?
Palatal arches to lower border of epiglottis
What does the pharynx connect?
Nasal and oral cavities with larynx and oesophagus
What muscle stretches the soft palate and elevates the pharynx?
Tensor veli palatini
What muscle elevates the soft palate and elevates the larynx?
Levator veli palatini
What do the tensor and levator veli palatini muscles do to the auditory tube? What is the purpose of this?
Assists with drainage from the middle ear
Equalises pressure between the middle ear and nasopharynx
What is the sensory innervation of the pharynx?
Nasopharynx: CNVb and IX
Oropharynx: CNIX
Laryngopharynx: CNIX and X
(CNIX supplies respiratory mucosa)
What is the epiglottis?
What is its role?
Cartilage of the larynx
Covers laryngeal inlet during swallowing to prevent aspiration
Where does the laryngopharynx begin and end?
Base of tongue/upper epiglottis to cricopharyngeus muscle
Which muscle has to relax in order to allow a food bolus to pass through the laryngopharynx into the oesophagus?
Cricopharyngeus
What epithelium lines the nasopharynx?
Respiratory epithelium: pseudostratified, ciliated, columnar
What epithelium lines the oropharynx and laryngopharynx?
Stratified squamous epithelium
Resists abrasion
What are the 3 pharyngeal constrictor muscles?
Superior constrictor
Middle constrictor
Inferior constrictor
What is considered the true upper oesophageal constrictor?
Cricopharyngeus muscle
What fills gaps between the pharyngeal constrictor muscles on the lateral and anterior portions?
Continuous internal fascia and mucosa lines all 3 pharyngeal constrictor muscles
What is the action of the pharyngeal constrictor muscles?
Reduce the diameter of the pharynx
Peristalsis to propel bolus into the oesophagus
What is the motor supply to the pharyngeal muscles?
All CNX except:
- Stylohyoid: CNIX
- Tensor veli palatini: CNVc
What could paralysis of CNX lead to in the pharynx?
Uncoordinated swallowing
Lack of gag reflex
The hyoid bone is an insertion point for which pharyngeal constrictor muscles?
Middle constrictor
Which structure extends between the styloid process and the hyoid bone?
What is its function?
Stylohyoid ligament
What is the anterior attachment point for the superior constrictor muscle?
Pterygomandibular raphe
What does the middle constrictor muscle insert into anteriorly?
Hyoid bone
Stylohyoid ligament
What are the complications of overgrown styloid processes?
Dysphasia
Facial pain on head rotation
Feeling of ‘something in throat’
Carotid artery compression
How do the pharyngeal constrictor muscles attach to eachother?
Attach posteriorly at the midline raphe
Where does the midline raphe extend from and to?
Base of skull to the ‘weak spot’ at the inferior aspect of the inferior pharyngeal constrictor muscle
What can form through the weak spot in the pharynx?
What might be the symptoms of this?
Pharyngeal (Zenker's) diverticulum: Herniation of the pharyngeal mucosa through the weak spot -Halitosis -Infection -Feeling of fullness in throat -Regurgitation of food on coughing
Coordinated peristalsis of constrictors and relaxation of cricopharyngeus causes what?
Drop in intrapharyngeal pressure to allow food bolus to progress downwards into oesophagus
What is the piriform fossa?
What is its function?
Gutter-like recess between central larynx and lateral thyroid cartilage
Helps to direct food and fluid to either side of the larynx to pass down laryngopharynx into the oesophagus without having to pass over the top of the epiglottis covering the airway.
Where may food become stuck on swallowing in the pharynx?
Vallecula
Piriform fossa
Which muscles shorten and elevate the pharynx on swallowing?
What is the effect of this?
Stylopharyngeus Palatopharyngeus Salpingopharyngeus Causes widening of the pharynx Allows intrapharyngeal pressure to drop helping swallowing of food
Where does the stylopharyngeus muscle originate from and attach to?
What is its motor innervation?
Styloid process to pharyngeal constrictor muscles
Motor supply from CNIX (only pharyngeal muscle with CNIX motor supply)
What does the salpingopharyngeus muscle extend from and to?
Auditory tube to pharyngeal muscles
What is the motor supply to the tensor veli palatini?
CNVc
What muscles make up the pharyngeal arches?
Where do they connect to?
Palatoglossus
Palatopharyngeus
Connect to underside of the soft palate
Where are the palatine tonsils located?
Between the palatoglossus and palatopharyngeus muscles
What can damage to CNX or CNVc cause in the soft palate?
Ipsilateral soft palate motor paralysis
How do the tensor veli palatini muscles stretch the soft palate?
By looping around bones behind the nasal choanae forming a right angle shaped muscle.
This pulls the soft palate tight rather than upwards
Which way will the soft palate and uvula deviate in CNVc or CNX damage?
Soft palate will deviate towards unaffected side, uvula will point to unaffected side
What does a CNIX or CNX lesion do to the gag reflex?
CNIX: Sensory loss: No gag reflex on affected side, full gag reflex on unaffected side
CNX: Motor loss: sensation but unilateral or no contraction
What is Waldeyer’s ring?
Ring of lymphoid tissue in naso and oropharynx Consists of: -Palatine tonsils -Lingual -Tubal -Adenoids
What can enlargement of adenoids cause?
Middle ear infections (reduced drainage of middle ear due to occlusion of auditory tube entrance)
Snoring: partial occlusion of airway
Swallowing problems
Food entering nasopharynx during swallowing
Altered voice
