exam 3 Flashcards
where does the cornea and conjunctiva get oxygen from during the day and night
day - tears
night - conjunctiva capillaries and
what is the lacrrimal lake
tear reservoir at medial canthus
What is the tear meniscus
at posterior edge of eyelid margins - area where tears collect at bottom of lid
what are the microplicae and microvilli
outer surface membrane of corneal and conjunctival epicells
It is the base of tear film
helps aid in adherence of tear film
name the parts of mucin and what makes it
- thin membrane associated mucin (glucocaylx)
- Thicker mucin (goblet)
name parts of tear film and what makes it
from cornea and out
- mucin (goblet cells)
- aqueous (lacrimal gland)
- lipid (meimbomian gland)
tears vs blood
tears have more potassium and chloride
blood has higher glucose
what are the following..
what happens when there is a decrease in them
lysozyme
lactoferrin
Lysozyme
- main protein of tear
-decrease = inflammatory dz
Lactoferrin
-protective to corneal and conjunctival epithelia
- decrease= aqueous dry eye
BOTH have antibacterial affect
what are acini
irregular arrangement of secretory cells around central lumen in lacrimal gland and accessory glands
sarcodosis causes what
enlarged lacrimal gland
name innervation of tears
parasympathetic
lacrimal nerve (branch from V1)
normal tear meniscus
0.5 mm
TBUT for dry eyes
less than 10 seconds
increased vasculature can show altered what
meimbomian glands
how long for warm compresses MGD
5 min BID
what is lagopthalmos
incomplete closure of lids
schirmers test vs phenol red vs tear osmolarity
both test aqueous production
schirmers is 5 minutes less that 5mm = dry
pheol red 15 min
<10 mm= dry
tear osmolarity
> or = 308 mOsm/L means dry
difference between two eyes of > 8 also means dry eyes
outflow of tears start with what
where do tears exit
capillary action tear lake to puncta.
exit inferior meaturs below inferior turbinate
size of
horizontal
vertical canaliculus
lacrimal sac
naso lacrimal duct
horizontal 8 mm
vertical canaliculus 2 mm
lacrimal sac 14
naso lacrimal duct 15
name and put size
explain what happens to your drainage system when you open and close your eyes
what about contracting and relazing horners muscle
how long to let collagen plug to dissolve
1-2 weeks
what covers sclera
sclera is the continuation of what
- tennons capsule
- bulbar conj
continuation of stroma
what do the the cornea and sclera have in common
difference in water content
similar collagen types
largely made of proteoglycan and collagen fibers
cornea has 78% water and cornea has 68% water
what accounts for lack of transparency of sclera
varieing size of collagen fibers
gag (glucosaminoglycans)( sclear has 1.4 gags that are found in the cornea)
68 % water
irregular space between c. fibers = light scattering
name to layers of episcleral and its blood supply
parietal
- superficial episcleral capillary plexus (radial and straight arrangment)
viceral
-deep episcleral cappilary plexus
(freely anastomosing)
what is ciliary injection (circumlimbal flush
inflammation of the cornea, iris, cilliary body causing deep vessels prominence
episcleral bveins are thought to play a role in what
IOP control
stroma thickness range
thinnest =
thickest=
stroma thickness range
0.5-1.0mm
thinnest = 0.3 mm recti insertion
thickest= 1.0 at pole
explain the scleral innervation
short posterior cilliary nerve supply the posterior portion
the long posterior cilliary nerve supply the anterior portion
they penetrate sclera at optic nerve sheath
axenfeld loops are
long cilliary nerve fibers loops in sclera
middle
posterior
anterior
aperatures
middle - vertex veins pass
posterior - long and short ciliary nerves and arteries pass
anterior - anterior ciliary
what is located at anterior scleral foramen
what about
posterior scleral foramen
cornea
optic neve exits here contain lamina cribosa
what is liamina cribosa and where is it located
weakeast area of the outer tunic located at the posterior scleral foramen
sieve
name the layers of the posterior pole of the stroma and their significance
- Outer
connects to dura arachnoid and optic nerve sheath - Inner
holds lamina cribosa
what are scleral hyaline plaques
they come with aging, darkish color close to the insertions of horizontal rectus not harmful
difference between
episcleritis
and
scleritis
episcleritis - involves superficial episcleritis plexus and conjunctiva
redish
scleritis - deep episcleral plexus
blueish color
to get distinction use phenylephrine 10% episcleritis blanches with this gtt
phenylephrine 2.5 % vs 10% diagnosis of what dz
2.5 % is conjunctivitis and episcleritis
10% is episcleritis and scleritis
what does this turn into at the limbus
corneal epithelium
corneal endothelium
corneal stroma
corneal epithelium > conjunctival epi
corneal endothelium > trabecular meshwork
corneal stroma> scleral stroma
what part of the eye is considered secondary immune tissue
conjunctiva
list and explain different Hyper sensitivity reactions
1 = allergy
2. = antibody cytotoxic
3. = immunocomplex
4. = delayed T cell
Name differences
IgA
IgG
IgE
_____IgA ______
- about 15 % of immuno g.
-in tears and mucous membranes
-produced by lacrimal gland and conj
____IgG_______
-75% of immuno g
-second line of deffense
- mediator of type 1 3 4 HSR
-found in tears and aquous humor
-can cross placenta and cornea
____IgE______
-anaphylactic mediator Type 1 HSR
- histamine release mast cell
-increase permiability to let wbc move through BV
what medication inhibits COX…. what does it stop the production of
what medication inhibits arachidonic acid pathway
what does it stop the production of
what medication inhibits COX…. what does it stop the production of
- NSAID, prostoglandinoids
what medication inhibits arachidonic acid pathway
what does it stop the production of
-corticosteroids , luekotryeins and prostoglandinoids
what is the eye associated lymphoid tissue
it is made of
1. conj
2. lacrimal gland
3. lacrimal drainage system
what immunoglobulin is produced more when sleeping
IgA
what are wessely immune ring
results from infection
antigen and AB interact and go across the limbal vasculature
it goes to the corneal stroma
activates complex
polymorphonuclear leukocytes go to stroma
normally cornea is devoid of Ag processing (t or F)
true
what is khodadoust line
endothelial rejection line … wbc make line and shoes rejection of cornea graft
What is responsible for making CSF
Choroid plexuses in ventricle
Intracranial anatomy is primarily supplied by
Internal carotid arteries and vertebral arteries
Basilary artery formed from what
Anastomoses of the two vertebral arteries
Basilary artery supplies what with blood
- occipital lobe
-cerebellum
-brainstem
Draw anterior circle circle of willis
Posterior communicating artery is close to what CN
How is this relevant to aneurysm near here
Aneurysm causes damage to CN III parasympathetic fibers causing blown pupil
(Remember normally parasympathetic fibers from CNIII causes constriction!)
What do emissary veins do
What direction do they flow
Connect extracranial veins to dural sinuses
Bidirection valveless (normal is external to internal but can change with intracranial pressure)
What layer contains dural venous sinuses
Where does the dural sinuses drain into
Duramatter
Drains in to internal jugular veins
Name two lamellae of dura mater
Periosteal
Meningeal
CFS returns to what
Superior sagital sinus
Deoxygenated blood from orbit and bran goes to what venous sinuses
Cavernous sinus
Cavernous sinus has what in it
CN III, CNIV, V1, V2 , CN VI internal carotid,
Out flow from cavernous sinus
- Superior petrosal sinus >sigmoid sinus>internal jugular
- Inferior petrosal sinus > jugular vein
Talk about carotid Cavernous fistula
Miscommunication between internal carotid (high pressure) and cavernous sinus (low pressure)
Sx
- increased IOP
-lid swelling
-red eye
-chemosis.
-pulsing proptosis
Veins of the scalp and veins inferior to skull drain into what
Dural sinuses
Where is the dural sinuese located
In between periosteal and meningeal lamellae
