Head and Neck: 2nd Term Flashcards
What branches of the internal carotid a. supply the scalp (2)? via what artery? Give their relation to one another.
Supraorbital (lateral), supratrochlear (medial), via ophthalmic branch of internal carotid a.
What provides sensory innervation behind the auricle (4) and where from?
Cervical plexus: Lesser occipital (C2) – scalp and neck posterior to auricle. Greater Auricular (C2-C3) –Skin over angle of mandible, over parotid gland, maxillary process, and bottom 2/3 of auricle.
Dorsal Rami C2-C3: Greater occipital n. (C2) –posterior most cranium. Third occipital n. (C3) – Area posterior to lesser occipital innervation. These aren’t from cervical plexus
What muscle of facial expression is not innervated by one of the five main branches of CN VII? What other muscle is innervated by this same nerve/branch?
Occipital belly of occipitofrontalis —> Posterior auricular branch of VII.
Auricularis posterior
What are the three parts to orbicularis oculi and what are their actions? What is the origin of the first two?
1.) Orbital part: Closes lids tightly/squinting (most superior part, so think that it has the most downward force).
ORIGIN: Medial part of medial palpebral ligament.
2.) Palpebral part (eyelid part): Closes lids gently.
ORIGIN: Lateral part of medial palpebral ligament.
3.) Lacrimal part: Dilate lacrimal sac.
#82 Lobo
What is the action of corrugator supercilii?
Draws eyebrows medially (demonstrating concern or worry), creating vertical wrinkles above nose.
- ) What is the origin of buccinator?
2. ) What is its shared action and with what muscle?
- ) Pterigomandibular raphe.
2. ) Prevents accumulation of food in the vestibule of mouth —> shared with orbicularis oris.
What is the terminal branch of the facial artery?
Angular artery at bridge of nose.
Which two nerves supply sensation to the posterior-most portion of the scalp? Describe them and their roots.
Dorsal rami of C2-C3, Not part of cervical plexus. Greater occipital (C2): Occipital scalp. 3rd occipital (C3): Lower occipital and sub-occipital regions. #12 njp, #35
Describe the pre- and post-ganglionic PSNS innervation to the parotid gland. What does PSNS stimulation do?
Pre-ganglionic: Inferior salivatory nucleus —> Lesser petrosal n. (Glossopharyngeal n., CN IX) —> Otic ganglion (PSNS ganglion) —post-ganglionic—> Auriculotemporal n. (CN V3) —> Parotid.
PSNS stimulation causes saliva production. #112 lobo
Describe four important relations of the parotid gland (two nerves, one artery, one vein).
1.) External carotid ends, giving off its two terminal branches – Superficial temporal a. and maxillary a.
2.) External carotid vein forms from the superficial temporal vein and maxillary vein.
3.) Auriculotemporal n. (V3) passes through
4.) Facial nerve (CN VII) – parotid plexus within gland; separates it into superficial and deep layers.
#111 lobo
- ) If the right spinal accessory nerve is injured, what SCM actions are compromised?
- ) What other muscle will be affected and how will it manifest?
- ) ipsilateral flexion and CONTRALATERAL ROTATION.
- ) Trapezius –ipsilateral shoulder will droop.
p. 991 Moore
What nerve innervates the skin over the parotid gland? Give its distribution.
Great auricular n. (C2-C3; from cervical plexus). Innervates skin of auricle, over angle of mandible, over mastoid process, and over parotid gland.
In which articular cavities of the TMJ do these movements occur – Gliding (protrusion and retraction), hinge (depression and elevation), rotational movements.
Protrusion/retraction: Upper cavity
Depression/elevation: Lower cavity
Rotation: Lower cavity.
Associate each type of motion at the TMJ with the muscles responsible —> Elevation (3), depression (3), protrusion (3), retrusion (2 –specify fibers), lateral movements/grinding/chewing (3 – specify laterality)
Elevation: Masseter, medial pterygoid, temporalis.
Depression: Lateral pterygoid, supra- and infrahyoids.
Protrusion: Lateral pterygoid, medial pterygoid, masseter.
Retrusion: Temporalis (post. oblique and horizontal fibers), and masseter.
Grinding/chewing/lateral mvmts: Temporal of same side, pterygoids of opposite side, and masseter.
#161 lobo, p.922
Which ligament serves as a swinging hinge for the TMJ? Where does it insert?
Sphenomandibular ligament –into the lingula of the mandible.
What is the intrinsic ligament of the TMJ? What movements does it prohibit/in which direction is it strengthened? What helps it?
Lateral ligament of the TMJ (aka temporomandibular ligament –essentially a thickened capsule at the condylar process) strengthens the joint LATERALLY and, along with the POSTGLENOID TUBERCLE, prevents POSTERIOR DISLOCATION.
What is the TMJs primary passive support?
Sphenomandibular ligament.
Which muscles does the mandibular division of trigeminal (CN V3) innervate (8)?
muscles of mastication (temporalis, medial and lateral pterygoids, masseter) tensor veli palatini, tensor tympani, ant. belly digastric, mylohyoid.
What muscle of mastication is the prime mover in TMJ protrusion? Others involved?
Lateral pterygoid (1˚), masseter, medial pterygoid.
Damage to INTRAarticular disc of TMJ will impede functions of which muscle and why?
LATERAL PTERYGOID because it inserts onto the joint capsule on the coronoid process head.
What are the two potentially dangerous anastomoses with the pterygoid venous plexus?
Anteriorly: w/ Facial a. via deep facial vein.
Superiorly: w/ Cavernous sinus via Emissary veins.
p.921 Moore —> GET THIS STRAIGHT
Between which two muscles does the pterygoid venous plexus lie?
pterygoids and temporalis (p.921 Moore)
What are two important nerve relations to the middle meningeal artery in the infratemporal fossa?
- ) Auriculotemporal n. from V3 forms a loop that m.meningeal passes through (i.e. auriculotemporal n. passes both anterior and posterior to middle meningeal a).
- ) Chorda tympani (of CN VII) passes inferior to middle meningeal as well.
p. 925 Moore, plate 50 Netter, #50 lecture
What nerve(s) provide taste and sensory to the anterior 2/3 of the tongue?
Taste: Chorda tympani n. (from CN VII).
Sensory: Ligual n. (V3).
They join one another in the infratemporal fossa, between the mandible and medial pterygoid, just inferior to the mandibular foramen
What nerve(s) provide sensory and post-ganglionic PSNS innervation to the parotid gland?
Auriculotemporal n. (CN V3) provides BOTH sensory and post-ganglionic PSNS fibers to the parotid gland.
What nerve provides articular (sensory) fibers to the TMJ?
Auriculotemporal n. (CN V3) #54
What are the 5 branches of CN V3 (mandibular div.)? Mnemonic?
BAIL —> Buccal n., Auriculotemporal n., Inferior alveolar n., Lingual n.
What nerve innervates the mandibular teeth and how does it get there?
Inferior alveolar nerve – Enters infratemporal fossa through foramen ovale —> Descends between medial and lateral pterygoids, deep to 1st part of maxillary a. and enters the mandibular foramen to supply mandibular teeth on its side.
plate 50, #56, p.925
What is the relationship between inferior alveolar nerve and lingual nerve in the infratemporal fossa?
Lingual lies ANTERIOR to inferior alveolar nerve —> #57, plate 50.
Describe the two most common TMJ dislocations, i.e. cause(s) and resulting injury.
- ) Most common, a sideways blow to the chin by a clenched hand (fist) when the mouth is open dislocates the TMJ on the side that received the blow.
- ) Anterior dislocation can occur due to excessive contraction of the lateral pterygoids (during yawning or taking a large bite). This causes the heads of the mandible to dislocate anteriorly pass anterior to the articular tubercles
p. 927
To administer a mandibular nerve block, where must one inject? Which nerves will be anesthetized?
In the mandibular notch of the ramus of the mandible (extra-oral approach). It will anesthetize the buccal, auriculotemporal, inferior alveolar, and lingual nerves.
p.927
How is the dura mater of the cranium different from that of the spinal cord?
Consists of two layers in the cranium: (1) Outer periosteal layer (periosteum on inner surface of calvaria) and, (2) Inner meningeal layer –continuous with spinal dura.