Pharynx Flashcards
What is the pharynx?
muscular and fibrous tube between the base of the skull and lower border of cricoid cartilage (upper margin of C6)
What is the function of the pharynx?
responsible for properly conducting food to the oesophagus and air into the lungs
What are the 3 regions of the pharynx and what are they defined by?
- nasopharynx posterior to the nasal cavity - choana
- oropharynx, posterior to the oral cavity - oropharyngeal isthmus
- larygopharynx, at the level of the larynx - laryngeal inlet
What muscles run between the torus tubaris and the pharynx and the palate?
salpingopharyngeus
salpingopalatine
What is torus tubaris?
inverted U-shaped cartilage;
2 muscles attach to the posterior and anterior arm
blue = torus tubaris
red = salpingophayngeus
green = salpingopalatine
What is the piriform fossa?
recess between phayngeal wall and quadrangular membrane
What are the circular muscles of the pharynx and what is their action?
- constrictor muscles
- superior pharyngeal
- middle pharyngeal
- inferior pharyngeal
What are the longitudnal muscles of the pharynx and what is their action?
- elevator muscles
- stylophayrngeus
- palatopharyngeus
- salpingopharynegus
red = superior pharyngeal
green = middle pharyngeal
blue = inferior pharyngeal
light blue = stylopharygeus
What is the sinus of Morgagni?
the space between the base of the skull and upper free border of superior constrictor
What is the sinus of Morgagni closed by?
pharyngobasilar fascia - keeps nasopharynx open
What is the pharyngobasilar fascia attached to?
medial pytergoid plate, internal to the attachment of the superior pharyngeal constrictor
What is the superior pharyngeal constrictor attached to?
pterygoid halmulus and pteryfomandibular raphe with the buccinator
What is the middle pharyngeal constrictor attached to?
hyoid bone and stylohyoid ligament
What is the inferior pharyngeal constrictor attached to?
oblqiue line of the thyroid cartilage, the cricoid cartilage
What is Killian’s dehiscence and what is likely to occur here?
inferior-most region of the inferior constrictor muscle, where the superior pharyngeal constrictor ends
Pharygoesophageal diverticulum (Zenker’s diverticulum)
Sinus of Morgagni closed by pharyngobasilar fascia
black = pharyngobasilar fascia
red = superior pharyngeal constrictor
green = middle pharyngeal constrictor
purple = inferior pharyngeal constrictor
Blue = pharyngeal raphe
Red = Killian’s dehisence
What is passavant’s ridge? And what does it surround? And give its function
(or palatopharyngeal sphincter)
mucosal ridge caused by superior pharyngeal constrictor or the palatopharyngeus
encircles the posterior and lateral walls of the nasopharynx
During swallowing it tocuhes to the soft palate to isolate the oropharynx from the nasopharynx
black = passavant’s ridge
Where do the pharyngeal elevator muscles descend from?
the skull and out into the inner surface of the pharynx
What is the action of palatopharyngeus? And why does it have unique actions?
- elevates pharynx and larynx
- draws the soft palate downwards
- brings the palatopharyngeal arch backwards
- separates the oral cavity from the pharynx
As both attachments are soft structures the muscle fibres can contract in both directions
Where does stylopharyngeus extend from?
extends from the styloid process to pass between the superior and middle pharyngeal constrictors and fan into tje internal pharyngeal surface
Where does salpingopharygeus descend into? And what is its function
descends into the pahrynx from the torus tubarius
opens the auditory tuve during swallowing
green = salpingopharyngeus
blue = palatopharyngeus
red = stylopharyngeus
Functions of the pharyngeal muscles
- elevators pull the pharynx superiorly and recieve bolus
- constrictors compress the lumen of the pharynx to push bolus towards oesophagus (contract from superior to inferior)
inferior pahryngeal constrictor has a lower circular part around the upper oesophagus called criciopharyngeal sphincter. What is its function
prevents air being drawn into the stomach during inhalation
What causes pharyngoesophgeal diverticulum?
lack of co-ordination between pharyngeal constrictors and cricopharyngeal sphincter
green = salpingopharyngeus
red = stylopharyngeus
Label the gaps and gateways
green = auditory tuve, levator palatini, tensor palatini
blue = (oropharyngeal triangle) stylopharyngeus muscle, glossopharyngeus nerve and sylohyoid ligament
black = internal branch of superior laryngeal nerve with superior laryngeal vessels (sensation to larynx above the vocal folds)
Red = recurrent laryngeal nerve (motor to intrinsic laryngeal inlet muscles except cricothyroid) with inferior laryngeal vessels
What is the arterial supply of the upper pharynx?
branches of the external carotid
What is the arterial supply of the lower pharynx?
branches of the inferior thyroid artery of thyrocervical trunk of subclavian artery
Describe the venous drainage of the pharynx
drainage by the pterygoid plexus will converge on the facial and internal jugular veins
Describe the lymphatic drainage of the pharynx
retropharyngeal, paratracheal and infrahyoid nodes –> on the deep cervical nodes
Where do the palatine tonsils drain to?
jugulodigastric
What is the only pharyngeal muscle innervated by the glossopharyngeal nerve?
stylopharyngeus
What are all but one of the pharyngeal elevator muscle supplied by?
vagus nerve
Where does the pharyngeal plexus lie and what does it include?
lies on the external pharyngeal wall
includes branches of C-IX, CN-X and cervical sympathetics
Where are the visceral efferents of the pharynx from?
vagus and facial nerves
What is the sensory supply of the nasopharynx?
maxillary division of the trigeminal nerve
What does the glossopharyngeal nerve give sensory supply to?
oropharynx, palatine tonsils, inferior surface of soft palate and posterior 1/3 of the tongue
pain may be referred to the middle ear
What is the sensory supply to the laryngopharynx, vallecula and epiglottis?
vagus
During chewing food needs to be kept between the occusal surfaces of the molar teeth. What muscles are responsible for this?
buccalis muscle, together with the tongue
During chewing the oropharyngeal isthmus must be closed. What muscles are responsible for this stating each of their actions?
- soft palate is pulled down: palatoglossus and palatopharyngeus
- Tongue is drawn slightly upwards: palatoglossus and palatopharyngeus
- palatoglossal and palatophayngeal arches moves medially like curtains
During swallowing the bolus is pushed towards the back of the oral cavity by raising the tip and body of the tongue towards the palate. What muscles are responsible for this?
mylohyoid and tongue muscles
During swallowing the tongue is pulled upwards and backwards to tip the bolus through the oropharyngeal isthmus and into the pharynx. What muscles are responsible for this?
styloglossus
During swallowing the soft palate is stretched and elevated. What muscles are responsible for this?
tensor veli palatini and levator veli palatini
elevated soft palate and passavant’s rudge separate the nasopharynx from the oropharynx. What muscle is responsible for this?
superior pharyngeal constrictor
the pharynx is elevated by the pharyngeal elevators
stylopharyngeus, salpingopharyngeus and palatopharyngeus as well as stylohyoid and digastric
What muscles close the laryngeal inlet?
tongue, aryepiglottic and thyroepiglottic muscles
What muscles push the bolus towards the oesophagus?
pharyngeal constrictors
