2. Superficial Face and Skull Interior Flashcards
How is the face innervated? (Different CN, sensory/motor, branches)
Motor: CN VII = facial nerve Sensory: CN V = trigeminal nerve V1 = opthalmic - orbit and forehead V2 = maxillary V3 = mandibular
What are the major actions of the following muscles: Orbicularis oculi Levator labii superioris Levator anguli oris Orbicularis oris Depressor labii inferioris Depressor anguli oris Platysma Buccinator
Orbicularis Oculi: palpebral part closes eyelid, orbital part forces eye shut
Levator labii superioris: raises upper lip
Levator anguli oris: raises angle of mouth
Orbicularis oris: lip pursing and mouth opening
Depressor labii inferioiris: lower bottom lip
Depressor anguli oris: lowers corner of mouth
Platysma: pulls skin of neck anteriorly, pulls angle of mouth and lip down
Buccinator: lateral wall of oral cavity, continuous with superior pharyngeal constrictor
What are the facial structures of the orbit/eyelid?
Upper and lower tarsal plates: c.t. of eyelid
Levator palpebrae superioris: lifts eyelid
Medial palpebral ligament
Orbital segment: barrier to infectioin (Dense c.t.)
What is the path tears take from start to end?
Lacrimal gland -> Superior fornix of conjunctiva -> Lacrimal papilla with lacrimal punctum (collects tears) -> Lacrimal canaliculus -> Lacrimal sac -> Nasolacrimal duct (to nose)
What are the 5 layers of the scalp? Where is the danger zone?
S - Skin C - subCutaneous fascia A - galea Aponeurotica L - loose c.t. (connecting A to P) P - periosteum
danger: in loose c.t. - area where blood/infection can spread
What are the layers and parts of each layer of the meninges?
Dura: periosteal dura (right on bone - no epidural space) and meningeal dura
Arachnoid: pressed against dura by CSF in subarachnoid space
Pia: follows all the contours of the brain
What are the differences between the types of bleeds: Epidural, Subdural, Subarachnoid?
Epidural: arterial (from middle meningeal artery), between dura and bone (“peels” dura away from bone), imaging has classic CONVEX shape towards brain - blood contained by dura, more serious
Subdural: venous from cerebral veins at superior sagittal sinus (veins tear at junction with sinus), between dura and arachnoid, Imaging has more irregular border b/c blood spreads more easily
Subarachnoid: arterial if from cerebral arteries (ruptured aneurysms), intracerebral blood spilling into CSF of subarachnoid space, follows contours of brain
What are Arachnoid Granulations?
Tufts of arachnoid extending into dural sinus
Valve mechanism to return old CSF to venous blood
(CSF is blood ultrafiltrate)
Can imprint bone due to soft pressure over decades
What are the dural sinuses? What is their fx? What vessels flow into and near it?
Describe the flow path.
Dural sinuses: venous channels b/w both layers of dura (meningeal and periosteal), all converge on internal jugular vein
fx: drain blood from brain and connect with veins of scalp
middle meningeal artery: supplies dura and bone
Flow: 1. Superior Sagittal Sinus -> Transverse Sinus -> Sigmoid Sinus -> Internal Jugular Vein
2. Inferior Sagittal Sinus (joining Great Cerebral Vein) -> Straight Sinus -> Transverse Sinus -> Sigmoid Sinus -> Internal jugular vein
3. Opthalmic/Deep Brain Veins -> Cavernous Sinus -> Superior/Inferior Petrosal Sinuses -> Start/End of Sigmoid Sinus -> Internal Jugular Vein
What is the Cavernous Sinus? What passes through it?
Collects venous blood from opthalmic and deep brain veins
Passes through it: CN 3, 4, 6, V2, Internal Carotid artery (could cause AV fistula)
Flanks body of sphenoid
What are the CN exits from skull? and where does middle mesangial artery enter skull?
I - cribiform plate of ethmoid II - optic canal of sphenoid III, IV, V1, VI - superior orbital fissure V2 - foramen rotundum V3 - foramen ovale VII, VIII - internal acoustic meatus IX, X, XI - jugular canal XII - hypoglossal canal
MMA - foramen spinosum
