Eye, Ear, and nose

Question 1

what are the 7 bones that make up the orbit? How do they shape the walls of the orbit?

Answer 1

frontal 
sphenoid 
ethmoid 
palatine 
lacrimal 
maxilla 
zygomatic 

**medial wall faces forward, lateral wall faces laterally

Question 2

what bone is the supraorbital notch on and what crosses through it

Answer 2

frontal

supraorbital nerve: V1 terminal branch

Question 3

what bone is the optic canal on and what crosses through it

Answer 3

sphenoid bone

optic nerve and ophthalmic artery

Question 4

what bone is the superior orbital fissure on and what crosses it

Answer 4

sphenoid

CN V1, ophthalmic division
CN III, IV, and VI
blood vessels

Question 5

what bone is the ethmoidal foramina on and what crosses it

Answer 5

ethmoid

ethmoidal nerves and arteries (nasociliary, V1 branches)

Question 6

what bone is the nasolacrimal canal on and what crosses it

Answer 6

lacrimal bone and maxilla

nasolacrimal duct: tear drainage

Question 7

what bone is the inferior orbital fissure on and what crosses it

Answer 7

sphenoid and maxilla

venous plexus

Question 8

how does the eye drain tears

Answer 8

tears flow inferomedial across eye to lacrimal canaliculi

lacrimal canaliculi flows into the nasolacrimal duct (opening in inferior meatus of nose)

Question 9

what is the innervation o the lacrymal apparatus

Answer 9

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)

Question 10

what is in the outer layer of the eye

Answer 10

sclera = white dense capsule 
cornea= clear dense capsule; allows light to pass through

Question 11

what is the choroid

Answer 11

2nd layer of eye

contains blood vessel plexus

Question 12

what is the retina

Answer 12

3rd layer of the eye

for sensory collection

Question 13

contents of the eyeball

Answer 13

iris: contains pupil (pupillary light reflex)

ciliary body: lens

vitreous body: humor

other structures include neuromuscular structures, permanent fat, and extraocular/extraorbital muscles

Question 14

what is the somatosensory innervation of the orbit

Answer 14

ophthalmic nerve and branches

nasociliary, frontal nerve, and lacrimal nerve

Question 15

what are the main branches from V1 from medial to lateral

Answer 15

nasociliary

frontal nerve

lacrimal nerve

NFL

Question 16

what is the blood supply to the orbit of the eye

Answer 16

ophthalmic artery from internal carotid

Question 17

what are the branches of the ophthalmic artery and the corresponding structures they supply in the orbit

Answer 17

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

Question 18

what is the sympathetic and parasympathetic motor innervation of the eyeball intrinsic muscles

Answer 18

sympathetic = postganglionic fibers from superior cervical ganglion (hike long/short ciliary nerve)

parasympathetic = preganglionic fibers form CN III to form ciliary ganglion

Question 19

what is the innervation and function of the ciliary muscle

Answer 19

ciliary body modulates size of lens

only innervated by postganglionic fibers from ciliary ganglion

Question 20

what is the function of the iris

Answer 20

when stimulated:

parasympathetic = constrict pupil (pupillary light reflex)

sympathetic = dilate pupil

AFFERENT = CN II 
EFFERENT = CN III

Question 21

What is Horners syndrome

Answer 21

sympathetic system is nonfunctional/not balanced

constricted pupil, eyelid ptosis, and no sweating on affected side

Question 22

what structures are contained in the eyelid

Answer 22

muscle tendons
orbital septum
palpebral ligament: lateral/medial
talus plate: superior/inferior

Question 23

neuromuscular supply of the eyelid

Answer 23

superior = V1 terminal branch 
inferior = V2 terminal branch 

anastomosis of external and internal carotid artery terminal branches

Question 24

function of eyelid

Answer 24

protect

facial expression