Session 4: The Infratemporal Fossa and Oral Cavity; The Mandible and Temporomandibular Joint Flashcards
What are the 2 separate bundles of the trigeminal that leave the brainstem?
The large sensory root
The small, medial motor root
What is the route of the trigeminal bundles after they leave the brain?
The two roots pass forwards below the tentorium cerebelli through an oval opening in the dura mater, on the apex of the petrous temporal bone, at the trigeminal impression.
What are the 3 divisions of the sensory root of the trigeminal?
Va - Opthalmic
Vb - Maxillary
Vc - Mandibular
Which of the sensory divisions does the motor root join?
Vc
Which foramen does Va pass through to exit the skull?
Supraorbital fissure via the cavernous sinus
Which foramen does Vb pass through to exit the skull?
Foramen rotundum
Which foramen does Vc pass through to exit the skull?
Foramen ovale
What are the branches of the opthalmic (Va) division of the trigeminal? (5)
Supraorbital (from frontal) Supratrochlear (from frontal) Lacrimal Long ciliary (from nasociliary) Short ciliary (from nasociliary)
What does the frontal nerve (Va) supply?
Skin of the forehead and anterior half of the scalp
What does the lacrimal nerve (Va) supply? What does it carry?
Skin of the upper eyelid
Carries parasympathetic from the pterygopalatine ganglion to the lacrimal gland.
What does the nasociliary nerve (Va) supply?
Ethmoidal and sphenoidal sinuses, and the root of the nose.
Describe the 2 main functions of the long ciliary nerve (Va).
1) sensory fibres from cornea
2) sympathetic fibres to dilator pupillae
What does the short ciliary nerve (Va) do?
Carries parasympathetic from the ciliary ganglion to the sphincter pupillae, the ciliary muscle and the ciliary body (for accommodation and constriction).
What are the branches of the maxillary (Vb) division of the trigeminal? (4)
Zygomaticotemporal
Zygomaticofacial
Infraoribital
Ganglionic
What does the zygomatic nerve (Vb) supply?
Skin of the lateral part of the forehead and over the cheek
What does the ganglionic nerve (Vb) supply?
Branches to the pterygopalatine ganglion.
What is a specific function of the zygomaticotemporal nerve (Vb)?
Carries parasympathetics from the ptergopalatine ganglion destined for the lacrimal gland (transfers them onto the lacrimal nerve (Va))
What does the infraorbital nerve (Vb) supply?
The maxillary teeth
What are the motor branches of the mandibular nerve (Vc)?
Nerve to medial pterygoid
Deep temporal
Lateral pterygoid
Nerve to masseter
What does the nerve to medial pterygoid (Vc) supply? (3)
Medial pterygoid
Tensor palati
Tensor tympani
What does the deep temporal nerve (Vc) supply? (1)
Temporalis
What are the sensory branches of the mandibular nerve (Vc)? (5)
Buccal Auriculotemporal Inferior alveolar Lingual Mental (from inferior alveolar)
What does the buccal nerve (Vc) supply?
Mucous membrane and skin of the cheek
What does the auriculotemporal nerve (Vc) supply?
TMJ, skin of upper half of ear and EAM, scalp above the meatus
What does the inferior alveolar nerve (Vc) supply? What else does this nerve contain?
Mandibular teeth
Also contains motor fibres which are given off in the nerve to mylohyoid.
What does nerve to mylohyoid (Vc) supply? Where does it come from?
Mylohyoid and anterior belly of digastric.
Comes off inferior alveolar nerve.
What does the mental nerve (Vc) supply?
Skin of lower lip
What is the lingual nerve joined by? What does it supply?
Chorda tympani (VII) Anterior 2/3 tongue, floor of mouth, sensory branches to submandibular ganglion.
Where is the temporal fossa?
The space occupied by temporalis muscle.
Where is the infratemporal fossa?
The space deep to the superior half of the mandibular ramus.
What are the contents of the infratemporal fossa? (6)
Pterygoid muscles Maxillary artery Pterygoid plexus of veins Branches of mandibular nerve (Vc) Otic ganglion Distal part of chorda tympani (VII)
Describe the pterygopalatine fossa.
A small pyramidal-shaped space that lies between the back of the orbit, the maxilla, and the sphenoid.
What is the position of the pterygopalatine fossa ideal for?
Connecting the eyes, nose and face as well as the infratemporal fossa and brain.
What are the main structures that run through the pterygopalatine fossa?
Maxillary nerve (Vb)
Terminal branches of maxillary artery
Pterygopalatine ganglion
Describe the boundaries of the pterygopalatine fossa.
Anterior wall - posterior surface maxilla
Posterior wall - pterygoid process of spenoid
Medial wall - perpendicular plate of palatine bone
Which foramen are connected with the pterygopalatine fossa?
Inferior orbital fissure Foramen rotundum (where Vb enters) Pterygoid canal (where nerve of pterygoid canal enters and carries autonomic fibres to ptergopalatine ganglion)
Which muscle forms the lateral walls of the oral cavity?
Buccinator
What is buccinator continuous with and from which point?
Continuous with the superior constrictor from the pterygomandibular raphe.
What does the pterygomandibular raphe run between?
Medial pterygoid plate of sphenoid and the mandible posterior to the mylohyoid ridge.
Which muscles lie medial to the pterygomandibular raphe and dominate the posterior border of the oral cavity? Discuss these muscles.
Palatoglossus and palatopharyngeus. They connect the tongue and the pharynx to the palate and are covered by mucous membrane.
What lies between palatoglossus and palatopharyngeus? What is an alternative name for them?
Palatine tonsils. They are also known as the tonsillar pillars.
What occupies the floor of the oral cavity?
The tongue.
How is the tongue divided and what are the 2 parts called?
It is divided into the anterior 2/3 (oral part) and the posterior 1/3 (pharyngeal part) by the sulcus terminalis.
What is the appearance of the anterior 2/3 of the tongue? What is covering it?
Velvety appearance, covered by small papillae. Mostly pointed filiform papillae, with mushroom shaped fungiform papillae among them.
Which papillae contain taste buds? Where are these located?
Fungiform papillae in the ant 2/3 tongue and circumvallate papillae lying in a row anterior to the sulcus terminalis.