Anatomy: Temporal & Infratemporal Fossae Part 2 Flashcards
Branches of the anterior division of V3 (mandibular division of the trigeminal nerve
- Nerve to the masseter
- Nerve to the lateral pterygoid
- Deep temporal nerves
- Buccal nerve
Nerve to the masseter innervates the ….
Masseter; gives a few sensory fibers to the anterior aspect of the temporomandibular joint because it’s in that vicinity
Nerve to the lateral pterygoid innervates the …
Pterygoid
Deep temporal nerves
Usually 2 (anterior & posterior) nerves; sometimes there’s a third (middle) nerve
Buccal nerve supplies ….
Sensory innervation!!!! To the skin and mucosa of the cheek
Buccal branch of 7 (facial nerve) = motor
Buccal branch of 5 (trigeminal nerve)= sensory
Branches of the posterior division of V3 (mandibular division of trigeminal nerve)
- Auriculotemporal nerve
- Inferior alveolar nerve
- Nerve to the mylohyoid
- Lingual nerve
Auriculotemporal nerve
- Originates as two roots that encircle the middle meningeal artery and reunite posterior to the artery
- Provides sensory innervation to the auricle, external auditory meatus, tympanic membrane, temporomandibular joint and scalp.
Inferior Alveolar Nerve
- Contains both sensory & motor fibers
- Enters mandibular foramen to supply all of the mandibular teeth
- Exits mandible at mental Foramen and continues as mental nerve
- -Before entering the mandibular foramen, the NERVE TO THE MYLOHYOID is given off
[alveolar = teeth]
Nerve to the mylohyoid
- A motor branch of the inferior alveolar nerve
- Innervates the mylohyoid and the anterior belly of the digastric
Lingual nerve
- Provides general sensory info (touch, pain, temp) to anterior 2/3 of the tongue and the mucosa of the floor of the mouth
- Joined high in the infratemporal fossa by the chorda tympani
A small, PARASYMPATHETIC GANGLION located inferior to the foramen ovale (in the temporal fossa) and medial to V3; Tympanic branch of CN IX forms the tympanic plexus (supplies the mucosa of the tympanic cavity)
Otic ganglion
Fibers in the Otic Ganglion
- Preganglionic Parasympathetic
- Postganglionic Parasympathetic
Fibers that leave the tympanic plexus in the form of the LESSER PETROSAL NERVE and synapse in the otic ganglion
Preganglionic Parasympathetic
Fibers that leave the otic ganglion and join the auriculotemporal nerve
Postganglionic parasympathetic
What do the postganglionic parasympathetic fibers leaving the otic gland innervate?
Parotid Gland
Where does the chorda tympani originate from?
CN VII (facial nerve) in the facial canal just above the stylomastoid foramen.
Path of the chorda tympani
- Enters tympanic cavity and courses across the medial side of the tympanic membrane (ear drum)
- EXITS THE TEMPORAL BONE VIA THE PETROTYMPANIC FISSURE
- Enters the infratemporal fossa where it JOINS THE LINGUAL NERVE (important b/c it is transmitting the taste fibers (sensory) of the anterior 2/3 of the tongue)
What special fibers does the chorda tympani contain, and what are they for?
Special sensory or tats fibers for the anterior 2/3 of the tongue
Fibers of the chorda tympani
- Preganglionic parasympathetic fibers
- Postganglionic parasympathetic fibers
Where do the preganglionic parasympathetic fibers of the chorda tympani synapse?
Submandibular ganglion
What do the postganglionic parasympathetic fibers from the chorda tympani supply?
Submandibular and Sublingual Salivary Glands
What are the two terminal branches of the external carotid artery?
Maxillary Artery
Superficial Temporal Artery
Terminal branch of the external carotid artery; Arises posterior to the neck of the mandible; Divided into 3 parts based on its relation to the lateral pterygoid muscle, with each part having a specific branch.
Maxillary Artery
Parts of the maxillary artery (wouldn’t ask us on the test)
- Mandibular Part
- Pterygoid Part
- Pterygopalatine Part
Part of Maxillary artery that lies between the neck of the mandible and the sphenomandibular ligament.
Mandibular (first) part
What accompanies the mandibular part of the maxillary artery?
AURICULOTEMPORAL NERVE
MAXILLARY VEIN
Five branches of the mandibular part of the maxillary artery
- Deep auriculotemporal
- Anterior tympanic
- Middle meningeal
- Accessory meningeal
- Inferior alveolar
Artery that supplies the external auditory meatus and the outer surface of the tympanic membrane
Deep auricular artery
Artery that passes through the petrotympanic fissure with the chorda tympani to supply the mucosa of the tympanic cavity
Anterior tympanic artery
Artery that passes between the two roots of the auriculotemporal nerve; passes through the foramen spinosum to enter the middle cranial fossa to supply the dura mater and skull
Middle meningeal artery
What is an epidural, and which artery does it correspond to?
Epidural: hematoma on top of the dura
Middle meningeal artery
Artery that passes through the Foramen ovale (along with V3) to supply the trigeminal ganglion and adjacent dura mater.
Accessory meningeal artery
Artery that accompanies the inferior alveolar nerve in the mandibular canal; exits the mental Foramen with the mental herve.
Inferior alveolar artery
What does the inferior alveolar artery give off before entering the mandibular foramen?
Artery to the mylohyoid
Part of the maxillary artery that passes anteriorly and superiorly in the infratemporal fossa.
Pterygoid (second) part
What are the branches of pterygoid part of the maxillary artery, and what accompanies them?
- Masseteric artery
- Anterior and Posterior deep temporal arteries
- Pterygoid arteries
- Buccal artery
-Branches all accompany branches of V3 (Mandibular part of the trigeminal nerve).
Masseteric artery supplies the …?
Masseter
Anterior & Posterior deep temporal arteries supply the …?
Temporalis muscle
Pterygoid arteries supply the …?
Medial and lateral pterygoids
Buccal artery supplies the …?
Buccinator
Skin of cheek
Mucosa of oral cavity
- *Buccal branch of 5 = sensory
- *Buccinator gets supplied by 7 = motor
Why is venous drainage in the brain/head so important?
Everything is interconnected: deep vessels are connected to superficial vessels and vice versa
A complex network of veins located partly between the temporalis and the pterygoid muscles
Pterygoid venous plexus
What mainly drains into the pterygoid venous plexus?
Most of the veins that accompany branches of the maxillary artery
What other deep venous structures does the pterygoid venous plexus communicate with?
- Cavernous sinus
- Inferior ophthalmic vein
- Facial vein
How does the pterygoid venous plexus communicate with the cavernous sinus?
Via small veins passing through the foramen ovale, foramen lacerum and sometimes a sphenoidal emissary (“weird little vein that runs into the cavernous sinus”) foramen.
How does the pterygoid venous plexus communicate with the facial vein?
Via the deep facial vein
