Dr. Scott ugh Flashcards
are arteries high or low pressure compared to veins?
high pressure
what is the outermost tunic of blood vessels? compare arteries and veins
Tunica adventitia
- collagen and connective tissue
- thicker in veins
what is the tunica media composed of? do arteries or veins have a thicker layer?
smooth muscle
-Arteries have a thicker tunica media
what is tunicac intima composed of? what is the outermost portion of it called?
- endothelial cells in direct contact with the lumen
- internal elastic lamina
what is the external elastic lamina?
the innermost portion of the tunica adventita
what do arteries drain into?
arterioles
arterioles are a primary site of what?
vascular resistance
what do arterioles drain to?
capillaries
what are capillaries composed of?
-endothelial cells and their basement membrane
wha are pericytes?
- they line the external surface of capillaries and help them dilate and constrict
- factor in diabetic retinopathy (proteins leak into retina)
what do capillaries do?
exchange nutrients and metabolic waste from arterioles and venules
branch retinal vein occlusion is due to what?
thicker tunica adventita on arteries and atherosclerosis
the right common carotid artery branches off of what? left common carotid?
Right common carotid: brachiocephalic
Left Common carotid: directly off the aorta
where does the common carotid bifurcate?
in the carotid sheath
the internal carotid artery enters the skull through what?
carotid canal
go draw the freaking cavernous sinus
do it
at the posterior opening of the optic canal, the internal carotid artery gives off wht branch?
the ophthalmic artery
what kind of nerve fibers are in the carotid sheath?
vagas nerve
-postganglionic sympathetic fibers
what would cause carotid cavernous fistula?
-venous drainage from the eye cannot get back to the cavernous sinus because there is too much pressure in the sinus.
if the ophthalmic artery doesnt come off of the ICA, what does it branch off of?
middle meningeal artery
the ophthalmic artery runs ________ to the optic nerve, then makes an abrupt turn________
runs lateral to the optic nerve then makes an abrupt turn over the optic nerve
what is the first and smallest branch off of the ophthalmic artery?
the central retinal artery
the ophthalmic artery has 3 regions and how many branches? name the regions and number of branches
Ocular: 2 branches
Orbital: 2 branches
Extraorbital: 7 branches
what are the branches in the ocular region of the ophthalmic artery?
central retinal arteryand ciliary arteries
the Central retinal artery pierces ___________ about 5-15mm from the posterior scleral aperature
pierces the dural sheath of the optic nerve about 5-15mm from the posterior scleral aperature
what is the lamina cribrosa?
thin piece of sclera made of collagen that act as support for the central retinal artery and vein
the central retinal artery gives off small ____ branches that supply__________
small pial branches that supply the pia mater tha surround the optic nerve
the central retinal artery gives off two branches which in turn bifurcate again. name them
divides into superior and inferior branches that then divide into temporal and nasal branches and those supply respective quadrants of the inner retinal layers
what is the major blood supply to the retina?
the central retinal arteryyyyyyyy
how many branches of long posterior ciliary arteries are there?
2! medial and lateral
what happens to central retinal artery and veins in glaucoma?
nasalization
the long ciliary arteries travel through what space?
suprachoroid space
what do the long ciliary arteries supply?
uvea anterior to equator
what is the uvea?
- iris
- ciliary body
- choroid
how many branches are there of the short ciliary arteries?
10-20
the branches of the short ciliary arteries form what?
an arterial loop around the optic nerve called the cirlce of Zinn Haller
what do the short ciliary arteries supply?
uvea posterior to the equator
the short ciliary arteries pierce___________ to enter suprachoroidal space
pierce posterior scleral aperatures
-provide postential site for metastisis
what are the orbital branches of the ophthalmic artery?
- lacrimal artery
- muscular arteries (branch into anterior ciliary arteries)
what does the lacrimal artery supply?
the lacrimal gland
what does the lacrimal artery branch into?
- muscular branches for lateral rectus
- palpebral arteries
- zygomatic artery
the lacriamal artery anastomoses with braches of what artery?
superficial termporal artery
the medial trunk of muscular arteries supply what?
- inferior rectus
- inferior oblique
- medial rectus
the lateral trunk of muscular arteries supply what?
- superior rectus
- superior oblique
- levator palpebrae superioris
the muscular arteries that supply the rectus branch into what?
anterior ciliary arteries
which EOM does not have 2 anterior ciliary arteries? (it has 1)
-the lateral rectus!
so how many anterior ciliary arteries are there total?
7
anterior ciliary arteries can do what two things?
- join long ciliary arteries to form the arterial circle of the iris
- stay superficial and give rise to anterior conjunctival arteries
between supraorbital and supratrochlear arteries, which one is more medial?
supratrochlear is more medial and supraorbital is more lateral
the supraorbital artery travels with what nerve?
frontal nerve
the supraorbital and supratrochelear arteries anastomose to form what?
the superficial temporal artery
what does the supraorbital artery supply?
-levator palpebrae superioris, superior rectus, superior oblique, scalp, upper eyelid
which ethmoid artery is larger?
the anterior ethmoidal artery is the largest
what does the posterior ethmoidal artery supply?
posterior ethmoidal and sphenoid air sinuses
the posterior ethmoidal artery runs between what two muscles?
-medial rectus and superior oblique
what does the anterior ethomidal artery supply??
medial and anterior ethmoid and sphenoid sinuses
- nasal cavity
- skin of the nose
what does the anterior ethmoidal artery pass through to supply the nasal cavity?
cribriform plate
what does the recurrent meningeal artery supply?
meninges in middle cranial fossa
-has to travel posterior through superior orbital fissure
the medial palpebral arteries are divided into superior and inferior based on their location to what?
medial palpebral ligament
the medial palpebral arteries anastomose with what to supply what?
- lateral palpebral arteries
- supply a portion of the eye lid
what are the terminal branches of the ophthalmic artery?
- supratrochlear
- dorsonasal
what do the supratrochlear artery and dorsonasal artery do to the orbital septum?
-it perforates it just above the trochlea
what does the supratrochlear artery supply?
skin to the medial forehead and scalp
the dorsonasal artery courses along_________ to supply ________
along the side of the nose to supply the lacrimal sac
what “part” of the ophthalmic artery lies outside of the muscle cone?
the nasofrontal artery
the nasofrontal artery gives rise to what two arteries?
supratrochlear and doronasal arteries
what are the branches of the external carotid artery that are involved in supplying the orbit?
- facial
- infraorbital
- superficial temporal
the facial artery loops around what?
the margin of the mandible
the facial artery changes its name to ________ at the ala of the nose
angular artery
what does the facial artery anastomose with at the medial canthus?
-infraorbital and dorsonasal arteries
what does the facial artery supply (in regards to the orbit)
lacrimal sac
the infraorbital artery is a branch of __________ that comes off of the external carotid?
maxillary artery
what fossa does the maxillary artery go through before it branches?
pterygopalatine fossa (enters through pterygomaxillary fissure)
the maxillary artery enters the orbit through ___________ and emerges as the infraorbital artery
inferior orbital fissure
what does the infraorbital artery supply?
- inferior rectus
- inferior oblique
- lower lid and cheek
what is the terminal branch of the external carotid?
superficial temporal artery
the superficial temporal artery gives off a branch, __________, that anastomoses with supraorbital and supratrochlear
anterior temporal artery
what does the superficial temporal artery supply?
lateral region around the orbit
the superficial temporal artery travels_______ towards ________
travels upward to the temporal fossa
why is it important that orbital veins do not have valves?
- you cannot stop infection if it gets in
- direction of blood flow is related to posture
in fundus photos, are veins or arteries darker?
arteries are lighter and veins are darker
the central retinal vein exits the eye through what?
the optic disc via lamina cribrosa
where does the central retinal vein drain to?
superior ophthalmic vein OR cavernous sinus
what do the vortex veins drain?
the choroid and ciliary body (uveal tunic)
how many vortex veins must you have (at least)
- 4-7
- at least one per quadrant
where do the vortex veins drain to?
- the ones in upper quadrants drain to the superior ophthalmic veins
- the ones in lower quadrants drain to the inferior ophthalmic veins
what do the anterior ciliary veins drain?
bulbar conjunctiva
what do the anterior ciliary veins drain into?
- muscular veins
- which in turn drains into the superior ophthalmic vein
when there is built up pressure in the cavernous sinus, what veins are dilated?
anterior ciliary veins
what does the infraorbital vein drain?
-lower lid and lower cheek
where does the infraorbital vein drain to?
pterygoid venous plexus
what is the largest vein in the orbit?
superior ophthalmic vein
the superior ophthalmic vein in formed by the joining of what?
supraorbital and angular vein
As the superior ophthalmic vein runs backwards, it picks up tributaries including what?
- central retinal veins
- upper two vortex veins
what does the superior ophthalmic vein drain to?
the cavernous sinus in the middle cranial fossa
what are the 5 things that are “left out” of the annulus of Zinn.
- lacrimal nerve
- frontal nerve
- trochlear nerve
-superior and inferior ophthalmic veins
what are the 5 things included in the annulus of zinn?
Superior division of oculomotor nerve
- nasociliary nerve
- inferior division of oculomotor nerve
- abducens nerve
- optic nerve
the inferior ophthalmic vein is formed from tributaries where?
from the floor of the orbit
what does the inferior ophthalmic vein drain?
- inferior rectus
- inferior oblique
- lateral rectus
- lower conjunctiva
- lacrimal sac
- lower vortex veins
what does the angular vein drain to?
facial vein
where does the facial vein pick up tributaries from?
veins of the face and the infraorbital vein
what kind of pressure system is the cavernous sinus?
a low pressure system!!!
where does the caverous sinus drain to?
internal jugular vein via jugular foramen
the cavernous sinus is a dural venous sinus situated on both sides of what?
the body of the sphenoid bone
the cavernous sinus runs from what to what?
from superior orbital fissure to petrous portion of temporal bone
does inside the orbit have any lymph drainage?
not inside
what part of the orbit has any kind of lymph drainage?
the lacrimal gland
the lateral part of the lacrimal gland drains where?
preauricular lymph nodes
the medial part of the lacrimal gland drains where?
submandibular nodes
what is the purpose of eyebrows?
to deflect sweat
what artery supplies the medial part of the eyebrow? vein?
supratrochlear artery
same
what artery supplies the lateral part of the eyebrow? vein?
supraorbital artery (contributions from lacrimal artery) same
what is the artery that supplies the lateral part of palpebrum?
lacrimal
what is the artery that supplies the medial part of palpebrum?
ophthalmic artery
in regards to palpebrum, the ophthalmic and lacrimal arteries branch into what arteries? those in turn branch into what arteries?
Ophthalmic: superior and inferior medial palpebral artery
Lacrimal: superior and inferior lateral palpebral artery
-EACH of those then branch into peripheral and marginal palpebral arteries
the marginal and peripheral palpebral arteries anastomose to form what in each palpebral?
the peripheral and marginal palpebral cascades
the peripheral and marginal cascades course between what?
orbicularis oculi and tarsal plate
what connects the peripheral and marginal arcades on either side of the tarsal plate?
vertical collateral branches
what gives the palpebral conjunctiva its pinkish hue?
the posterior collateral branches that supply it
what vein drains the lateral part of the palpebrum?
superficial temporal vein
what drains the medial part of the palpebrum?
- angular vein
- superior and inferior ophthalmic veins
lymph from the lateral 2/3 of palpebrum drains where? medial 1/3?
Lateral: preauricular
Medical: submandibular
what would conjunctival pallor (white palpebral conjunctiva) indicate?
anemia
why is that area called the danger triangle of the facec?
there are no valves to stop infection from flowing once it gets in.
what artery supplies the forniceal conjunctiva?
branches fro peripheral palpebral arcade
what vein drains the forniceal conjunctiva?
small tributaries that drain into anterior ciliary veins
posterior conjunctival arteries arise from what?
peripheral palpebral arcade
where does the posterior conjunctival arteries extend up to?
up to 4mm from the corneal limbus
what does the posterior conjunctival artery supply?
bulbar and fornix
what is situated between the posterior conjunctival arteries and the corneal limbus?
anterior conjunctival arteries
the anterior conjunctival arteries form what?
- superficial pericorneal plexus(conjunctiva)
- deep pericoreal plexus(episclera)
what do the anterior conjunctival arteries arise from?
anterior ciliary muslces
what is ciliary flush
- seen in keratitis
- anterior conjunctival arteries from superficial ring in conjunctiva and deep
what are the avascular structures of the eye?
- cornea
- sclera
- crystalline lens
- trabecular meshwork
- vitreous humor
why is there not any blood in the cornea?
you would not want it to get in the way of sight
what is the cornea dependent on?
- aqueous humor
- tear film
- pericorneal plexus
is all of the sclera avascular?
nah. some structures above and below it are vascular
how could you tell the difference between episcleritis and scleritis?
episcleritis would not move when you pull on the conjunctiva
what arteries supply the choroid?
short posterior ciliary arteries
-anastomose with recurrent branches from long ciliary arteries
what holds 85% of total ocular blood volume?
the choroid
what drains all of the parts of the uvea?
vortex veins
what artery supplies the ciliary body (intermediate uvea)
long ciliary arteries
what makes up the minor arterial circle of the iris?
radial vessels from long ciliary arteries
what causes rubeosis iridis?
-lack of oxygen, so new blood vessels form without collagen around them
what artery supplies the optic nerve?
- pial plexus from ophthalmic artery and central retinal artery
- ring of zenn hallar(?) has some contribution
what drains the optic nerve?
venous pial plexus
-drains into central retinal vein
the retina has what kind of vascular supply?
dual vascular supply
the inner retinal layers are supplied by what artery?
central retinal artery
the outer layers of the retina are supplied by what artery?
choroidal vasculature
what is the ONLY communication between the retinal arterial system and the choroidal system?
the cilioretinal artery
