eye and orbit

Question 1

nn of the orbit

Answer 1

CN: 2,3,4,5,6

know foramen

Question 2

cn II inn what at eye

Answer 2

special sensory of retina

Question 3

cn 3 inn what at eye

Answer 3

sup, med, inf rectus, inf oblique and levator palpbrae superioris
motor inn

Question 4

cn 4 inn what at eye

Answer 4

motor to sup oblique

Question 5

cn 5 at eye

Answer 5

cutaneous sensory (v1 and v2)

Question 6

cn6 at eye

Answer 6

lat rectus motor inn

Question 7

basic mechanism of eye function

Answer 7

photons to the retina=photoreceptors
carried by optic nn to optic chiasm where crossover of lateral field occurs
R to L side of brain and vice versa
some visual info goes to other parts of the brain for processing and is used for head and eye movement coordination

Question 8

label

Answer 8

Question 9

label

Answer 9

Question 10

lesion at optic chiasm

Answer 10

loss of lateral fields of view

Question 11

label

Answer 11

Question 12

white part of the eye

Answer 12

sclera

Question 13

meningial coverings, CSF blockage?

Answer 13

meningial layers extend onto the optic nn until it reaches the eye
CSF blockage could impact the optic disc

Question 14

choroid of the eye

Answer 14

vascular layer, supplies eye with nutrients

Question 15

ciliary body

Answer 15

will pull on or relax the lens

contracts for near vision allowing lens to be compressed for focusing, zonular fiber are relaxed during this

Question 16

iris

Answer 16

colored portions with two mm layers
outer longitudinal and inner circular
will constrict inner circular to constrict pupil(para from CN 3)
will constrict outer long to dialate (sym)

Question 17

label

Answer 17

Question 18

label

Answer 18

Question 19

macula

Answer 19

region with the highest density of photoreceptors

usually avascular but surrounded by lots of vessels

Question 20

levator palpbrae superioris action

Answer 20

elevates superior eyelid

Question 21

superior oblique action

Answer 21

abducts
depresses
medial rotation

Question 22

inferior oblique action

Answer 22

abduct
elevates
lat rotation

Question 23

superior rectus action

Answer 23

elevates
adducts
medial rotation

Question 24

inferior rectus action

Answer 24

depresses
adducts
lateral rotation

Question 25

medial rectus action

Answer 25

adduction

Question 26

lateral rectus action

Answer 26

abduction

Question 27

sup oblique action explained

Answer 27

will rotate eye medially, down and abduct due to the trochlaer attatchment

Question 28

ciliary ganglion contents and function

Answer 28

contains para/sym fibers
parasympathetics from CN III and sympathetics from the superior cervical ganglion
psotgang sympathetics but contains the synapse between pre and post gang para
will give branches that can hitch rides on CN V branches to go to the mm of the lens and pupil
allows for accomodated vision (change in lens size) and pupil size adjustment

Question 29

pterygopalatine ganglion

Answer 29

pregang para from CN 7 (greater petrosal nn), postgang sym from the superior cervical ganglion
will provide branches to the nasal and lacrimal glands

Question 30

submandibular ganglion

Answer 30

recieves parasym fiber (pregang) from CN7 (chroda tympani)
post gang sym from the superior cervical ganglion
control of salivary glands

Question 31

otic ganglion

Answer 31

receives parasym from CN IX (pregang)
sym from sup cervical ganglion (postgang)
will provide ANS inn to the parotid gland

Question 32

sympathetics of head/neck

can hitch rides on?

Answer 32

provided from the thoracolumbar distribution of sympathetic
synapses of pregang and postgang at the superior cervical gang
will then project postgang fibers to the ganglia of head/neck, hitch ride along the carotid Aa to reach this area
can then hitch rides on the branches of CN to reach targets

Question 33

manifestations of loss of sympathetics to the head/neck

Answer 33

tosis=droppy eye lids
miosis=small pupil
anhidrosis=inability to sweat normally

Question 34

Aa supply of the eye

Answer 34

int carotid will provide the opthalamic Aa 
this then branches to supply the eye 
lacrimal aa 
ant/post ethmoidal aa 
supratrochlear 
supraorbital 
ant/post ciliary (short/long)  
central Aa of retina 
dorsal nasal Aa 
zygomatic facial and temporal Aa

Question 35

vitreous humor flow

Answer 35

from region of the greater arterial circle of iris to the scleral venous sinus

Question 36

vv drainage of eye

Answer 36

sup/inf opthalamic vv drain to cavernous sinus, as well as supraorbital vv
infraorbital and angular drain to the pterygoid plexus

Question 37

blowout fracture of the eye

Answer 37

possible with direct blow to break boen inferior to the orbit=herniation of adipose tissue but also mm
eye may not move properly

Question 38

retinal detatchment

Answer 38

retina detatches from the choroid layer

can lead to blindness with cell death if not fixed

Question 39

retinal detatchment

Answer 39

retina detatches from the choroid layer

can lead to blindness with cell death if not fixed

Question 40

cataracts

Answer 40

clouded lens, fixed with artifical lens

Question 41

glaucoma, kinds

Answer 41

obstruction to vitreous humor flow>usually out of the scleral venous plexus
can be open/closed angle
open: the trabecular mesh is blocked=increase in P which decreases blood flow to the eye and causes subsequent cell death
closed: increased P due to iris closure over trabecular meshwork=cannot drain, same result as open

Question 42

hyphema

Answer 42

bleeding in the eye from trauma

Question 43

CN 3 paralysis presentation

Answer 43

mm it inn will be out
does not inn the lat rectus or sup oblique, these are active and cause abduction, depression and medial rotation
also dialted pupil as there are no parasym to the ciliary gang from cn3