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37 Cards in this Set
- Front
- Back
Where is the masseteric region?
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On the side of the head, inferior to the zygomatic arch and lateral to the ramus of the mandible.
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What is the masseter?
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A muscle of mastication. One of the strongest muscles in the body.
O: zygomatic arch I: outer surface of the ramus of mandible Inv: Masseteric n. (motor branch of the mandibular division of the trigeminal nerve V3) A: Elevation of the mandible, can also produce lateral movement (grinding) |
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Where is the temporal region?
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On the side of the head above the external auditory meatus and the zygomatic arch. Includes the temporal fossa that contains the temporalis muscle.
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What is the temporalis?
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A muscle of mastication.
O: temporal fossa (?) I: coronoid process of mandible Inv: deep temporal n. (branch of the mandibular division of the trigeminal nerve V3) A: contraction of anterior fibers-elevates mandible contraction of posterior fibers-retracts mandible |
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Describe the fibers of the temporalis muscle.
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Oriented both vertically (anterior fibers) and horizontally (posterior fibers).
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Where is the infratemporal region?
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Inferior to the temporal fossa and deep to the ramus of the mandible.
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What are the boundaries of the infratemporal region?
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Lateral wall - ramus of mandible
Anterior wall - body of the maxilla (eggshell thickness) Medial wall - lateral palte of the pterygoid process Roof - formed by the under surface of the greater wing of the sphenoid bone |
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What is the pterygopalatine fossa?
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A triangular space medial to the site where the lateral plate of the pterygoid process hits the maxilla.
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What openings are in the pterygopalatine fossa?
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The opening from the infratemporal fossa to the pterygopalatine is called the pterygomaxillary fissure. This joins with the inferior orbital fissure at a right angle.
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What are the contents of the pterygopalatine fossa?
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-pterygopalatine ganglion
-3rd part of the maxillary artery |
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What perforates the infratemporal fossa?
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-foramen ovale
-foramen spinosum |
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What are the contents of the infratemporal fossa?
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-pterygoid muscles
-maxillary artery -pterygoid plexus (a venous plexus) -several nerves |
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What is the medial pterygoid muscle?
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The most medial structure in the infratemporal region.
O: medial surface of the lateral pterygoid plate I: medial surface of the rams Inv: nerve to the medial pterygoid muscle A: elevation of mandible, lateral (grinding) movements of mandible |
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What is the lateral pterygoid muscle?
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O: roof and medial wall of the infratemporal fossa
I: 1. anterior part of the neck of the mandible and 2. on the articular disc of the temporomandibular joint Inv: depression and protrusion of the mandible |
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What nerve enters the infratemporal fossa?
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The mandibular nerve (CN V3) of the trigeminal nerve enters via the foramen ovale. Forms a trunk about 2-3 mm.
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What are the branches of the trunk of the mandibular n.?
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-meningeal n.
-nerve to the medial pterygoid m. |
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What is the anterior division of the mandibular nerve?
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Mainly motor. Branches include:
-masseteric n. -deep temporal n. -buccal (sensory) n. -nerve to the lateral pterygoid muscle |
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What is posterior division of the mandibular nerve?
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Mainly sensory. Branches include:
-auriculotemporal n. -lingual n. -inferior alveolar n. |
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What artery supplies the infratemporal fossa?
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The maxillary artery, is divided into three parts.
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What does the second branch of the maxillary artery supply?
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All the muscles of mastication and the buccinator muscle.
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What branches of the maxillary artery do we need to know?
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-middle meningeal a. (to dura of brain)
-inferior alveolar a. (to lower teeth) -sphenopalatine a. |
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What is the pterygoid plexus?
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Forms around the pterygoid muscles, ends as the maxillary vein, which eventually joins the superficial temporal vein to form the retromandibular vein.
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What are the important connections does the pterygoid plexus have?
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Has important connections with the:
1. cavernous sinus via the foramen ovale 2. facial vein via the deep facial vein 3. pharyngeal plexus of veins |
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What is the otic ganglion?
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A parasympathetic ganglion, important relay station for the preganglionic parasympathetic fibers of the glossopharyngeal n. (CN IX) destined for the parotid gland.
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What brings preganglionic fibers to the otic ganglion?
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The lesser petrosal n. descends through the foramen ovale bringing preganglionic fibers to the otic ganglion; the postganglionic fibers travel with the auriculotemporal n to the parotid gland.
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What is the temporomandibular joint?
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TMJ. Has 2 joint cavities that are filled with synovial fluid, joint between mandible and temporal bone.
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What are the bony parts of the TMJ?
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-head of the mandible
-articular surface of the mandibular fossa -articular tubercle of the temporal bone |
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What is the articular disc?
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It caps the head of the mandible and projects forward under the articular tubercle, dividing the joint cavity into upper and lower compartments.
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What type of movement does the articular disc allow?
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Simple hinge movements. One on each side, upper and lower cavities.
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What type of movement does the lower joint cavity of the TMJ allow?
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Depression and elevation of the mandible.
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What type of movement does the upper joint cavity of the TMJ allow?
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Protrusion and retraction of the mandible.
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What ligaments are external to the TMJ joint capsule?
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-lateral temporomandibular ligament (the thickened joint capsule)
-stylomandibular ligament -sphenomandibular ligament |
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What muscles of mastication elevate the mandible?
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-vertical fibers of temporalis
-masseter -medial pterygoid |
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What muscles of mastication depress the mandible?
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Accomplished by gravity and:
-anterior belly of digastric -mylohyoid -lateral pterygoid |
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What muscles of mastication move the mandible laterally?
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Ipsilateral (same side):
-temporalis -masseter Contralateral: -medial pterygoid |
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What muscles of mastication protrude the mandible?
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Just the lateral pterygoid.
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What muscles of mastication retract the mandible?
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Just the horizontal fibers of the temporalis.
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