2. GI Tract Pharynx and Swallowing.pptx Flashcards
What is the difference between the piriform fossa and the larnygeal inlet?
Piriform fossa – between the quadrangular membrane of the larynx and the side wall of the pharynx
The laryngeal inlet is between the aryepiglottic folds
What makes up the pharyngobasilar fascia? 4
Superior, middle and inferior constrictors
+ Elevators
What are the 4 points of pharyngeal attachment?
- Medial pterygoid plate of sphenoid
- Pharyngobasilar fascia attaches to the cartilage of the auditory tube
- Levator Palati arises from the apex of the petrous temporal bone, inside is the pharyngeal attachment
- The fascia, and the posterior, midline pharyngeal raphe formed by the constrictors attaches to the pharyngeal tubercle
3 structural features of the hyoid bone?
Body
Greater horn
Lesser horn
The stylohyoid ligament attaches to the lesser horn to suspend the hyoid from the styloid process of the skull
What are the attachments of the pharyngobasilar fascia and the 3 constrictors?
- Pharyngobasilar fascia attaches to the medial pterygoid plate (posterior nasal choanae), internal to the attachment of
- Superior constrictor, which continues to form the pterygo-mandibular raphe with buccinator
- Middle constrictor attaches to the hyoid bone (greater and lesser horns) and stylohyoid ligament
- Inferior constrictor attaches to the oblique line of the thyroid cartilage (thyropharyngeus), the cricoid cartilage (cricopharyngeus) and to the fascia on cricothyroid
The free, lower edge of which structure contributes to the palatopharyngeal sphincter that separates the naso from the oropharynx during swallowing?
The superior constrictor
What structure fills the gap above superior constrictor and then lies internal to it?
The pharyngobasilar fascia
What seals the “Gap” below the superior constrictor?
“Gap”, sealed by tongue muscles, fascia and mucous membrane, but allowing neurovascular structures to enter the oral cavity
What structure is between Buccinator and Superior constrictor?
Pterygomandibular raphe
What nerve supplies:
- Cricothyroid
- Larynx
- Sensation to larynx above vocal folds
External laryngeal nerve to cricothyroid
Recurrent laryngeal nerve passing deep to inf constrictor to reach the larynx
Internal laryngeal nerve – sensation to larynx above the vocal folds
_____ fascia lies externally, all around the muscular pharynx and blends with the pretracheal fascia
Buccopharyngeal fascia lies externally, all around the muscular pharynx and blends with the pretracheal fascia
What prevents air being drawn into the stomach during inhalation?
The inferior constrictor has a lower, circular part, crico-pharyngeus that forms a spinster around the upper oesophagus
What nerve supplies all the pharyngeal constrictors?
The pharyngeal branch of the vagus (X)
What is a potential consequence of uncoordinated contraction of cricopharyngeus?
May excessively raise pressure in the pharynx
At which point does the superior constrictor layer end?
What is it’s importance?
The cricopharyngeal sphincter (which leaves only 2 layers, the middle and inferior constrictor)
This allows a potential weakness (The dehiscence of Killian) through which a pharyngeal diverticulum may occur, particularly in cricopharyngeal incoordination
What are the points of insertion of the pharyngeal elevators?
Importance?
From skull to fan out into the inner surface of the pharynx. May send some fibres to the thyroid cartilage as well.
** ensures simultaneous elevation of the pharynx and larynx
Name the pharyngeal elevators?
Palatopharyngeus
Stylopharngeus
Salpingopharyngeus
All on internal pharynx aspect
Function of palatopharyngeus?
Elevates the pharynx and larynx
Draws the soft palate downwards and brings the palatopharyngeal arch towards the midline to help palatoglossus (the pillars of the fauces) separate the oral cavity from the pharynx
Main function: Pharyngeal elevator
Stylopharyngeus:
Attachments
Innervation
Main function
Stylopharyngeus descends from the styloid process to the internal pharyngeal surface
It is the only muscle supplied by the glossopharyngeal nerve (IX)
Main function: Pharyngeal elevator
Salpingopharyngeus:
Attachments?
Function?
Innervation?
From cartilage of auditory tube
Function: Elevator of pharynx and larynx. Opens auditory tube during swallowing for pressure equalisation in middle ear
Innervation: Vagus nerve
Nervous supply of palatine tonsil?
Lymph drainage?
Glossopharyngeal nerve
Lymph drainage to Jugulodigastric node
Swelling of which two tonsils may cause obstruction of the airway and auditory tube and why?
Causing…
The pharyngeal tonsil/ adenoid on the roof of the nasopharynx,
and also the tubal tonsil as they are at the opening of the auditory tube
Causing?
-Mouth breather
-Middle ear infection
What is the vallecula?
The vallecula is a pit or fossa between the tongue and epiglottis, waiting for foreign bodies!
Arterial supply of the upper and lower pharynx?
Upper pharynx - branches of the external carotid artery
Lower pharynx – branches of the inferior thyroid branch of thyrocervical from subclavian
Venous drainage of the pharynx?
Include pterygoid plexus but essentially converges on the facial and internal jugular veins
Lymph drainage of pharynx?
Includes:
- Retropharyngeal nodes
- Paratracheal nodes
- Infrahyoid nodes
To converge on the deep cervical nodes
Which parts of the pharynx receive their sensory supply by the following nerves:
- Glossopharyngeal (IX)
- Vagus (X)
- Maxillary (V2)
Oropharynx, palatine tonsil, inferior aspect of soft palate and posterior 1/3 tongue – Glossopharyngeal (IX)
[Referred pain to middle ear]
Laryngopharynx, vallecula and epiglottis - Vagus (X)
Nasopharynx – Maxillary (V2)
Motor supply of the pharynx?
PS, secretomotor- Vagus(X) and Facial (VII)
Musculature- Vagus except stylopharyngeus which is glossopharyngeal
5 stages of swallowing
- The bolus is pushed towards the back of the oral cavity by raising the tip and body of the tongue upwards towards the palate – mylohyoid and tongue intrinsic muscles
- Styloglossus pulls the tongue upwards and backwards to tip the bolus through the oropharyngeal isthmus and into the pharynx
- The soft palate is tensed (tensor palati) and elevated (levator palati) to sit within Passavant’s ridge and separate the naso from the oropharynx
The palatoglossal and palatopharyngeal arches relax and move laterally - The pharynx and larynx have already been elevated by the longitudinal muscles - stylopharyngeus, salpingopharyngeus and palatopharyngeus; stylohyoid and digastric may also help
- Relaxation of the elevators allows the pharynx and bolus to descend, while sequential contraction of the constrictors pushes the bolus towards the oesophagus
