Eye, Ear, and nose Flashcards
what are the 7 bones that make up the orbit? How do they shape the walls of the orbit?
frontal sphenoid ethmoid palatine lacrimal maxilla zygomatic
**medial wall faces forward, lateral wall faces laterally
what bone is the supraorbital notch on and what crosses through it
frontal
supraorbital nerve: V1 terminal branch
what bone is the optic canal on and what crosses through it
sphenoid bone
optic nerve and ophthalmic artery
what bone is the superior orbital fissure on and what crosses it
sphenoid
CN V1, ophthalmic division
CN III, IV, and VI
blood vessels
what bone is the ethmoidal foramina on and what crosses it
ethmoid
ethmoidal nerves and arteries (nasociliary, V1 branches)
what bone is the nasolacrimal canal on and what crosses it
lacrimal bone and maxilla
nasolacrimal duct: tear drainage
what bone is the inferior orbital fissure on and what crosses it
sphenoid and maxilla
venous plexus
how does the eye drain tears
tears flow inferomedial across eye to lacrimal canaliculi
lacrimal canaliculi flows into the nasolacrimal duct (opening in inferior meatus of nose)
what is the innervation o the lacrymal apparatus
sympathetic = postganglionic axons from superior cervical ganglion to form deep petrosal nerve
parasympathetic = preganglionic axons from CN VII to form greater petrosal nerve ( becomes nerve to pterygoid canal)
what is in the outer layer of the eye
sclera = white dense capsule cornea= clear dense capsule; allows light to pass through
what is the choroid
2nd layer of eye
contains blood vessel plexus
what is the retina
3rd layer of the eye
for sensory collection
contents of the eyeball
iris: contains pupil (pupillary light reflex)
ciliary body: lens
vitreous body: humor
other structures include neuromuscular structures, permanent fat, and extraocular/extraorbital muscles
what is the somatosensory innervation of the orbit
ophthalmic nerve and branches
nasociliary, frontal nerve, and lacrimal nerve
what are the main branches from V1 from medial to lateral
nasociliary
frontal nerve
lacrimal nerve
NFL
what is the blood supply to the orbit of the eye
ophthalmic artery from internal carotid
what are the branches of the ophthalmic artery and the corresponding structures they supply in the orbit
central retinal artery: inner vitreous body
ciliary artery: ciliary body
supraorbital artery: scalp and eyelid
ethmoidal artery and Dorsal nasal artery branches
lacrimal artery: lacrimal gland
what is the sympathetic and parasympathetic motor innervation of the eyeball intrinsic muscles
sympathetic = postganglionic fibers from superior cervical ganglion (hike long/short ciliary nerve)
parasympathetic = preganglionic fibers form CN III to form ciliary ganglion
what is the innervation and function of the ciliary muscle
ciliary body modulates size of lens
only innervated by postganglionic fibers from ciliary ganglion
what is the function of the iris
when stimulated:
parasympathetic = constrict pupil (pupillary light reflex)
sympathetic = dilate pupil
AFFERENT = CN II EFFERENT = CN III
What is Horners syndrome
sympathetic system is nonfunctional/not balanced
constricted pupil, eyelid ptosis, and no sweating on affected side
what structures are contained in the eyelid
muscle tendons
orbital septum
palpebral ligament: lateral/medial
talus plate: superior/inferior
neuromuscular supply of the eyelid
superior = V1 terminal branch inferior = V2 terminal branch
anastomosis of external and internal carotid artery terminal branches
function of eyelid
protect
facial expression
