Which nerves innervate the outer ear?
- auiculotemporal (V3)
- great auricular (cervical plexus)
Which nerves innervate the concha?
SA (VII, X)
Which nerve innervates the mucosa of the middle ear cavity?
Where does the footplate of stapes lie?
Oval window (opposite fluid filled chambers of cochlea->hairs in organ of Corti-> CN VIII)
What nerve crosses the lateral wall of the middle ear cavity?
- Chorda tympani (VII)
- anterior 2/3 tongue (SS)
- sub-mandibular ganglion (VE-para/pre) via lingual nerve(V3) -> SUBLINGUAL AND SUBMANDIBULAR GLANDS
What is the tensor tympani?
- muscle attaches to malleus and auditory tube to dampen vibration
- innervatied by V3(BM)
What is the promontory?
medial wall bony elevation, where the tympanic plexus forms from tympanic br(IX Glossopharangeal)->lesser petrosal nerve (VE-para/pre to otic ganglion -> parotid
What structures relate to anterior wall of middle ear?
- auditory tube opening (middle ear->nasopharynx), equilize pressure
What are the structures of posterior wall of middle ear?
- Aditus (opening) to mastoid antrum (air cells/sinuses)
- facial canal: facial nerve as it exits stylomastoid foramen (gives off chorda tympani)
What does the stapedius do?
- Originates from small pyrimidal eminence connects to stapes
- dampens stapes vibration
- CN VII (BM)
What is the tegmen tympani?
- roof of middle ear
- floor of middle cranial fossa
What is on the floor of the middle ear cavity?
Internal Jugular Vein
What are the 5 layers of the eylids?
- 1. Skin
- 2. SubQ
- 3. Muscles: orbicularis oculi, levator palpebrae, superior tarsal muscle(symp/post fibers)
- 4. Tarsofacial layer: plate& glands (oil prevent stickiness)
- 5. Conjunctiva: palpebral
What is the course of tears?
Lacrimal gland->duct-> sup & inf fornix->puncta->analiculi->sac->nasolacrimal duct->inferior meatus
What is superior tarsal muscle?
VE-symp-post widens eyelids
Which muscles elevate/depress eyball?
- elevate: superior rectus, inferior oblique
- depress: inferior rectus, superior oblique
Which muscles adduct/abduct the eyeball?
- adduct: medial, superior & inferior rectus
- abduct: lateral rectus, inerior & superior obliques
Which medially/laterally rotate eyball?
- medial: intorsion-superior rectus & oblique
- lateral: extorsion-inferior rectus & oblique
What is the only branch of internal carotid artery?
- Opthalmic a (optic canal)
- branches: central, lacrimal,posterior ciliary, supraorbital, posterior ethmoid, anterior ethmoid, dorsal nasal, supratrochlear
How is eyeball drained?
- corresponding veins to superior opthalmic->cavernous sinus
- inferior opthalmic is connected to pterygoid venous plexus
What nerves does CN III carry?
- goes through superior orbital fissure (3-6)
- SA, SE (everything except superior oblique and lateral rectus
- VA-para/pre to ciliary ganglion via INFERIOR division
What is the fundus?
- posterior part of eyball
- optic disc: sensory fibers & vessels of eyes conveyed-> BLIND SPOT
- macula lutea: lateral to optic disc w depression called fovea centralis area of most acute vision
What is the cornea innervated by?
- V1 ciliary nerves
- transparane avascular sensitive
What are the divisions of V1?
- cell bodies in trigeminal ganglion
- Lacrimal, frontal (supraorbital, supratrochlear), nasociliary (long ciliary), poterior/anterior ethmoid, infratrochlear
- anterior ethmoid gives rise to external nasal n.
What are the 3 layers of eyeball?
- 1. Fibrous: sclera & cornea
- 2. Vascular: iris, ciliary body, choroid (vascular)
- 3. Retinal
What is the ciliary body?
- smooth muscle & vasculature that connects the choroid and iris
- attachment for lens via zonular fibers
- controls thickness (focus & accomidation) of lens
- VE-para/post from ciliary ganglion fibers from CN III
Which muscles control the size of the pupil?
- sphincter pupilla (parsymp)
- dilator pupillae (symp)
How is the retina organized?
pigmented(light absorbing) & neural(rods & cones->bipolar->ganglion cells (CNII)
What does the vitreous chamber do?
- transmits light
- holds retina in place
- suppport lense
What does the aqueous humor do?
nourishes cornea and lens
What is the innervation of the lacrimal gland?
VE-para/post from pterygopalatine ganglion (hitchhike along V2 and zygomatic temporal->lacrimal
Where do all sympathetic post fibers synapse?
- Superior Cervical Ganglion (fibers from T1-L2)
- jump on ICA/ECA
Where is the ciliary ganglion?
- between optic nerve and lateral rectus
- VE para/pre from edinger westphal nucleus -> sphincter pupillae & ciliary body
Where do the sym post fibers to orbit go?
- originate from superior cervical ganglion
- Long ciliary V1 to dilator pupillae (doesn't go through ciliary ganglion)
- blood vessels of eye (ganglion)
What is the pathway to ciliaris & sphincter pupallae?
- VA pathway
- Edinger Westphal->inferior CN III-> ciliary ganglion
- Short ciliary n-> muscles
What fiber types does the short ciliary nerve contain?
- motor: VE-para/post (to ciliary body & sphincter pupillae)
- sympathetic: symp/post (to blood vessels)
- Sensory: SA (from V1)
Which fascias make the carotid sheath?
investing, prevertebral, pretracheal
What innervates carotid body/sinus?
- body: chemo, X
- sinus: baro, IX
Which muscle splits to allow digastric to go through?
Where are symp/pre cell bodies?
- lateral gray horn unless splanchnic
- symp/post: symp chain ganglion or preaortic
What are the types of VA fibers?
- pain(sympathetic) cell bodies in DRG
- reflex (parasymp) cell bodies in vagal sensory ganglia or S2-4 DRG