Oral Cavity Part 2 Flashcards
What is the parotid gland and what takes place there?
- serous gland found in the retromandibular fossa
- parotid duct (which crosses the masseter muscle superficially, pierces buccinator and opens into oral vestibule)
- where terminal branching of external carotid artery and facial nerve takes place
Where would you find Stensen’s duct in the oral vestibule?
opposite the second maxillar molar tooth
What are the sublingual glands?
- mucous glands found above the mylohyoid muscle beneath the mucous membrane of the floor of the mouth
- open by 8-20 separate ducts into the floor of the mouth along the sublingual fold
What are the submandibular glands?
- mixed mucous and serous glands found beneath the lower border of the body of the mandible
- ducts empty into the oral cavity at the sublingual papilla
What is sialolithiasis and where is the most common site of this?
- salivary gland stones
- most commonly found in the submandibular gland
Where is the pharynx found?
between base of the skull and lower border of cricoid cartilage (C6)
Describe the divisions of the pharynx
- nasopharynx: posterior to nasal cavity with choana opening
- oropharynx: posterior to oral cavity with oropharyngeal isthmus opening
- laryngopharynx: level of the larynx with laryngeal inlet opening
How are the salpingopharyngeal (superior) and salpingopalatine (inferior) folds formed?
salpingopharyngeus and salpingopalatine muscles run between torus tubarius and pharynx and palate respectively forming the folds
Where is the piriform fossa?
between the quadrangular membrane of the larynx and the side of the pharynx
Name the muscles of the pharynx
Circular muscles (constrictor muscles):
- superior pharyngeal
- middle pharyngeal
- inferior pharyngeal
Longitudinal muscles (elevator muscles):
- stylopharyngeus
- palatopharyngeus
- salpingopharyngeus
What are the attachments of the constrictor pharyngeal muscles?
- superior: pterygoid hamulus and pterygomandibular raphe with buccinator
- middle: hyoid bone and stylohyoid ligament
- inferior: oblique line of thyroid cartilage and cricoid cartilage
What is the joint place of insertion of the constrictor pharyngeal muscles?
pharyngeal raphe (which attaches to pharyngeal tubercle)
What is the role of the pharyngobasilar fascia?
closes the gap between the occipital bone and superior pharyngeal constrictor muscle
What is Kilian’s dehiscence?
the inferior most region of the inferior pharyngeal constrictor muscle, weak area
What is the Sinus of Morgagni?
the space between the base of the skull and the upper free border of the superior pharyngeal constrictor muscle
What is Passavant’s ridge/palatopharyngeal sphincter?
- mucosal ridge caused by superior pharyngeal constrictor or the palatopharyngeus
- encircles the posterior and lateral walls of the nasopharynx
What separates the nasopharynx and the oropharynx when swallowing?
Passavant’s ridge/palatopharyngeal sphincter
What are the actions of palatopharyngeus?
- elevates the pharynx and larynx
- draws the soft palate downwards
- brings palatopharyngeal arches backwards
- separates oral cavity from the pharynx
Name the pharyngeal elevator muscles
- palatopharyngeus
- stylopharyngeus
- salpingopharyngeus
Describe the anatomical position of stylopharyngeus
- extends from styloid process
- passes between superior and middle pharyngeal constrictors
- fan into the internal pharyngeal surface
Describe the anatomical position of salpingopharyngeus
- descends into the pharynx from torus tubarius
- opens the auditory tube during swallowing
Describe the functions of the pharyngeal muscles
- elevators pull pharynx superiorly and receives bolus
- pharyngeal constrictors compresses the lumen of pharynx and push bolus towards oesophagus
- inferior pharyngeal constrictor has cricopharyngeal sphincter that prevents air being drawn into the stomach during inhalation
Describe the arterial supply of the pharynx
- upper pharynx: branches of external carotid artery
- lower pharynx: branches of inferior thyroid artery of thyrocervical trunk of subclavian artery
Describe the venous drainage of the pharynx
pterygoid plexus that converges on facial and internal jugular veins
Describe lymphatic drainage of the pharynx
- retropharyngeal nodes
- paratracheal nodes
- infrahyoid nodes
- all drain to deep cervical nodes
- palatine tonsils drain to jugulodigastric
Describe the sensory supply of the pharynx
Maxillary division of trigeminal nerve:
- nasopharynx
Glossophryngeal nerve: oropharynx, palatine tonsils, inferior surface of soft palate and posterior 1/3rd of tongue
Vagus nerve:
- laryngopharynx
- vallecula
- epiglottis
Describe the sequence of swallowing
- bolus pushed towards back of oral cavity towards palate by mylohyoid and tongue muscles
- palatoglossal and palatopharyngeal arches relax and move laterally
- tongue pulled upwards and backwards to tip bolus through oropharyngeal isthmus and into pharynx by styloglossus
- soft palate stretched and elevated by tensor veli palatini, levator veli palatini
- elevated soft palate and passavant’s ridge separate nasopharynx from oropharynx by superior pharyngeal constrictor
- pharynx is elevated by pharyngeal elevators
- laryngeal inlet closed
- bolus pushed towards oesophagus by pharyngeal constrictors
Describe how infant anatomy is different from that of an adult
- omega shaped epiglottis
- tongue with central groove
- fat pads for generation of intra-oral suction
- close proximity of soft palate and epiglottis
- elevated larynx that is tucked under epitglottis
