Oral Cavity And Its Boundaries Flashcards
What does the oral cavity divide into?
Vestibule and oral cavity proper
Where is the vestibule?
Between teeth and gums internally, lips and cheeks laterally
Where is oral cavity proper?
Bounded anteriorly and laterally by dental arcades. Roof is hard palate and floor is muscles of the floor of the mouth.
Where does the blood supply of the teeth drain?
Teeth drain into the pterygoid venous plexus, draining into maxillary vein into the retromandibular vein. Possibility that they can drain into emissary veins and then into the cavernous sinus.
Blood supply to the teeth
Maxillary artery
Inferior alveolar artery and vein through the mandibular canal
Posterior and anterior superior alveolar artery and vein
Nerve supply to lower arcade of teeth
Mandibular division gives anterior and posterior divisions:
Posterior division will give inferior alveolar never through mandibular canal which will travel through mandibular turning into the mental nerve to give sensation to inferior 1/3 of teeth
Nerve supply to upper arcade of the teeth
Maxillary division
Infraorbital nerve through infraorbital groove in the floor of the orbit. It goes anteriorly in the infraorbital canal opening into the Infraorbital foramen, giving 2 branches - the anterior and middle superior alveolar nerves which innervate the upper teeth.
What is the hard palate made from and what does it separate?
Separates oral from nasal cavity. Made mainly of the palatine process of maxilla and horizontal plate of palatine bone.
Route of the maxillary nerve to the palate
Maxillary nerve enters the pterygopalatine fossa through the foramen rotundum, giving some branches here. The pterygopalatine fossa opens inferiorly to the greater and lesser palatine canals which travel inferiorly to open into the greater and lesser palatine foramens.
What goes through the greater palatine foramen?
Greater palatine artery (branch of the descending palatine artery which comes off the 3rd part of maxillary artery) goes through the greater palatine foramen
Which foramen does the nasopalatine nerve go through and what fibres does it carry?
Nasopalatine nerve is a branch of maxillary nerve. Carries sensory fibres and parasympathetic fibres from the pterygopalatine ganglion. Exits through the incisive foramen.
What exits through the lesser palatine foramen?
Lesser palatine artery (branch of descending palatine which is branch of maxillary artery)
Lesser palatine nerve (branch of maxillary nerve which originates in pterygopalatine fossa)
What does the lesser palatine nerve supply?
Gives sensory information to the soft palate.
What nerve communicates with the pterygopalatine ganglion to innervate small salivary glands?
Greater petrosal nerve branches off the facial nerve. It is the preganglionic neuron that communicates with the pterygopalatine ganglion. Postganglionic parasympathetic and sympathetic fibres will join branches of the maxillary nerve and hitchhike to get to the palate to innervate e.g., smaller salivary glands.
What are the muscles of the soft palate made of and why?
Innervation by the pharyngeal plexus of the vagus since they all originate from the 4th pharyngeal arch, except tensor veli palatini which originates from the 1st arch with the muscles of mastication, being innervated by the medial pterygoid nerve of CNV3.
