H&N 8: Pharnyx Flashcards
Where does pharynx extend from?
cranial base to lower border of cricoid cartilage where it becomes continuous with oesophagus.
What is pharynx?
- mucosa lined muscular tube lying behind + communicating with nasal, oral + laryngeal cavities
- part of digestive + resp system
Where is opening of cartilaginous part of pharyngotympanic tube?
between base of skull + pharynx
What is function of soft palate?
- sep oral from nasal cavity
- when swallow, raised against pharyngeal wall + blocks off nasal cavity so can’t breathe + swallow at same time
What is Waldeyer’s ring?
lymphoid tissue between roof of mouth, palatine tonsil + back of tongue + is protective
What does larynx do during swallowing?
moves up + forwards to get out of the way
What prevents food entering larynx?
vocal + vestibular folds close to form sphincter
What helps food + fluid get down into oesophagus?
epiglottis gets pulled under tongue which creates conduit
Where does nasopharynx lie?
above the soft palate and behind the nares
What is floor of nasopharynx formed by?
soft palate which is elevated during swallowing
What forms major part of post. wall of nasopharynx?
sup. constrictor
What is on the lat. wall of nasopharynx?
- opening of the pharyngotympanic (auditory) tube
- behind it lies a small mass of lymphoid tissue.
What is in roof of nasopharynx?
more lymphoid tissue, the adenoid or pharyngeal tonsil.
Where does oropharynx lie?
beneath soft palate and communicates anteriorly with the oral cavity.
How is oropharynx sep from nasopharynx?
by the raising of the soft palate.
What lies ant. in oropharynx?
- palatoglossal + palatopharyngeal arches
- palatine tonsil in space between them
What is palatine tonsil supplied by + sig?
lingual, ascending pharyngeal + lesser palatine which anastomose freely in the tonsil + therefore haemorrhaging poses a threat during tonsillectomy.
What is the laryngopharynx?
that part lying adjacent to the larynx projecting upwards into the pharynx
Where does the laryngopharynx end?
at C6 by funnelling into the oesophagus
Which system does pharynx belong to?
digestive system even though air passes through it.
List 4 layers of phaynx
- Mucosal coat
- Submucosa
- Muscular coat
- Areolar coat
What is the submucosa?
- contains a tough fibrous coat which anchors the pharynx to the base of the skull
- pharyngeal muscles attach to tubercle on basiocciput
What is muscular coat?
5 pairs of muscles (sup., middle + inf. constrictor) which form an outer semicircular layer and two inner longitudinal muscles
What is areolar coat?
covers the exterior of the pharynx termed the
buccopharyngeal fascia.
List muscles of pharynx
- sup., middle + inf. constrictor
What is function of constrictor muscles?
During swallowing, the muscles contract sequentially as peristaltic waves
What is nerve supply to constrictor muscles?
vagus nerve with motor fibres contributed by the cranial part of accessory
Where does palatopharygeus arise + insert?
- from palatal aponeurosis + auditory tube.
- passes inferiorly to insert into posterolat part of pharynx + also post. part of hyoid bone + thyroid cartilage
What is course of stylopharyngeus?
originates from styloid process + passes inferomedially through gap between sup. + middle constrictors + enters pharynx where its fibres mingle with palatopharyngeus + insert in a similar fashion.
What are + is function of long. muscles?
palatopharyngeus + stylopharyngeus - raise pharynx + larynx during swallowing
Where is raphe along constrictor muscles attached?
to tubercle at base of skull
Where does sup. constrictor arise?
- post. part of raphe + buccinator attaches to ant. part
Where does middle constrictor arise?
hyoid bone
Where does inf. constrictor arise?
thyroid + cricoid cartilage
What is motor supply to pharyngeal muscles?
all except stylopharyngeus supplied by pharyngeal branches of vagus
- stylopharyngeus supplied by glossopharyngeal
What is sensory supply to pharynx?
- glossopharyngeal nerve is main sensory supply
- V2 supplies soft palate + roof of pharynx
- vagus supplies area around pharyngeal inlet
What is blood supply to pharynx?
- ascending pharyngeal + sup. thyroid (branches of ext. carotid)
- inf. thyroid (branch of subclavian)
- facial + maxillary arteries
- provide rich anastamosis
What is venous drainage of pharynx?
veins form plexus + communicate with pterygoid plexus - deep to mandible
Describe lymphatic drainage of pharynx
- many lymph vessels pass to deep cervical lymph nodes
- some post. ones enter retropharyngeal nodes which lie between prevert + buccopharyngeal fasciae
- lymph nodes track back into jugulo-digastric nodes
- ant. nodes drain into jugulo-omo-hyoid node
