hi let's talk about your pharynx your pharynx is the proximal portion of your arrow digestive
pathway so it's it's a common space for both the respiratory and the digestive systems the farik's
consists of three spaces a nasal pharynx which is continuous with your nasal cavity and oral pharynx
which is continuous with both the nasopharynx and the oral cavity and a laryngopharynx which
is contiguous with both the oral pharynx the larynx and the esophagus let's take a look
at the nasopharynx the nasopharynx begins at the choanae which are the internal nares and
ends at the soft palate contained within the nasopharynx is the opening for the auditory or
pharyngotympanic tube the furring of tympanic tube is a cartilaginous and bony structure that
connects the pharynx with the middle ear so if you are to pinch your nose and push air
that would provide an opening into your fringo tympanic tube you would hear a little bit of a
crinkle so that's equilibration of pressure I don't recommend doing that I certainly don't
recommend doing that very forcefully along the superior margin of your nasal pharynx is
your pharyngeal tonsil or your adenoid this is a posterior view of the pharynx in its entirety we
can see the nasal pharynx so there are the choanae there in there there's the soft palate and below
that line of the soft palate is the oral pharynx and that's going to extend inferiorly to the
pharyngoepiglottis fold and superior portion of the epiglottis and so within that oral pharynx we have
a uvula we have Palatine tonsils not pictured in there tonsillar fossa laterally and then the
lingual tonsils now the tonsils are going to form a complete ring around the pharynx severely we
have the adenoid or pharyngeal tonsil laterally we have the Palatine tonsils and in fearly we
have the lingual tonsils the border between the oral pharynx and the oral cavity is known as the
fauces so from the soft palate inferiorly to the epiglottis and anteriorly to the fauces is
the oral pharynx the laryngopharynx runs from the pharyngoepiglottic fold and epiglottis down to the
inferior border of the cricoid cartilage and it contains two very important openings there's the
laryngeal Inlet which would be the pathway for gases to exchange between the lower respiratory
system and the upper respiratory and we also have the entrance to the esophagus which would be the
pathway that food-and-beverage would take down to the stomach the pharynx is comprised of two sets of
muscles there's an outer layer of circumferential constrictors and an inner longitudinal layer
of muscles that outer layer of circumferential constrictors consists of three sets of muscles
there's a superior pharyngeal constrictor which originates on the skull and the buccomandibular raphe and it
meets its counterpart along the pharyngeal raphe medially there's a middle pharyngeal constrictor
which originates on the hyoid bone and it meets its counterpart along the pharyngeal raphe and
then there's an inferior pharyngeal constrictor which originates on the larynx there are two parts
to this inferior pharyngeal constrictor there's the thyropharyngeal part which originates on
the thyroid cartilage of the larynx and the cricopharyngeal part which originates on the
cricoid cartilage of the larynx these two come together to form the inferior constrictor which
meets its counterpart along the pharyngeal raphe as well now these three muscles will serially
constrict the pharynx so as to move food distally along deep to these muscles are the
inner longitudinal muscles one of which we can see here this is the stylopharyngeus it originates on
the styloid process of the temporal bone and it inserts down into the pharynx the other are the
palatopharyngeus the palatopharyngeus originates on the bony palate and the soft palate and inserts
on the thyroid cartilage of the lyrics and the salpingopharyngeus which originates adjacent
to the auditory tube and also inserts on the thyroid cartilage and the pharynx these three
inner longitudinal muscles both widen and shorten the pharynx so is to help during swallowing these
muscles are innervated by the pharyngeal plexus that has three components descending from the
jugular foramen are the vagus nerves cranial nerve 10 the vagus nerves provide pharyngeal branches
these pharyngeal branches are the efferent or the motor component of the pharyngeal plexus they're
going to innervate efferently all of the pharyngeal muscles with the exception of the stylopharyngeus
muscle the stylopharyngeus muscle is going to be innervated by the glossopharyngeal nerve and
you can see that the glossopharyngeal nerve has a very close association with the
stylopharyngeus muscle it's found upon the muscle immediately posterior to it glossopharyngeal
nerve also descends from the brain through the jugular foramen and is the efferent component
to the pharyngeal plexus so there are branches to the glossopharyngeal nerve that are sensory from
the pharynx back up through the glossopharyngeal nerve the glossopharyngeal nerve will be there for
afferent to the entirety of the pharynx with the exception of the nasopharynx which is innervated
by v2 or the a branch of the maxillary nerve in addition to the Vagus and glossopharyngeal
nerves the pharynx or the pharyngeal plexus also includes contributions or branches from the
superior cervical ganglion of the sympathetic trunk so as to help modulate blood flows so
we've talked about the phayrnx its subdivisions and its muscular constituents and they're
nervous inputs let's take a look at regions adjacent and distal to the pharynx thank you