Lecture 1/11 Flashcards
what side do the nasal retinal fibers go?
to the opposite side
cross
what side do the temporal retinal fibers go?
stay on the same side
how many layers are in the LGN?
6 layers
what does the LGN do?
takes information from both eyes, puts it together to have stereoscopic vision
what are optic radiations?
from LGB to primary visual cortex
where is the primary visual cortex located and what Broadman area?
in the occipital lobe of the brain
-Broadman’s area 17
where are the association areas of the primary visual cortex?
Bradman’s areas 18 and 19, surrounding primary area (17)
what kind of organization does the primary visual cortex have?
retinotopic organization- point by point representation
2 main arteries supplying the eye, orbit, and surrounding structures
- internal carotid artery (ICA)
2. ophthalmic artery
what is the origin of the internal carotid artery (ICA)?
starts as a bifurcation of the common carotid (at the level of the thyroid)
where does the ICA enter the skull?
carotid foramen
after the ICA enters the skull through the carotid foramen, where does it go?
it goes forward and medially through carotid canal and then vertical into the middle cranial fossa
does the ICA go through the foramen lacerum?
no, it goes OVER the foramen lacerum
what are the branches from the ICA?
- ophthalmic to the orbit
- branch to the brain (that splits into 2): anterior cerebral artery and middle cerebral artery
what is the origin of the ophthalmic artery?
a branch off the ICA (At the level of the anterior clenoid)
where does the ophthalmic enter the orbit?
through the optic foramen/ optic canal
where is the ICA located compared to the optic nerve?
lateral and inferior
what happens to the ophthalmic nerve as it enters the orbit?
it crosses up over the top of the optic nerve and goes to the medial side of the orbit
how many branches does the ophthlamic give off and how many are to the orbital vs. ocular?
11 main branches
(-8 orbital branches
-3 ocular branches)
list the 8 orbital branches of the ophthalmic artery:
- lacrimal
- supraorbital
- muscular
- anterior ethmoidal
- posterior ethmoidal
- medial palpebral
- supratrochlear
- dorsal nasal
list the 3 ocular branches of the ophthalmic artery:
- central retinal artery (CRA)
- short posterior ciliary
- long posterior ciliary
what branch is the lacrimal and on what side is it located?
it is the 2nd branch off the ophthalmic and branching on the lateral side
describe the path of the lacrimal artery
arises near optic foramen, passes anteriorly along superior border of LR muscle, then anteriorly to lacrimal gland, then passes through lacrimal gland
what does the lacrimal artery supply?
the eyelids and conjunctiva of the eyelids (on the lateral side)
list the branches of the lacrimal artery
- lateral palpebral
- inferior and superior
- zygomatics
- muscular branches
the lateral palpebral branch of the lacrimal artery supplies:
the upper eyelid and lower eyelid on lateral side
the interior and superior branches of the lacrimal are called _____ and supplies the:
palpebral arcades
-will supply lateral eyelids
what are the two zygomatic branches of the lacrimal artery and what do they supply?
- zygomatico-temporal and zygomatico-facial
- supply side of face
muscular branches of the lacrimal artery supply:
the lateral rectus
where does the supraorbital branch arise?
coming off the ophthalmic artery on medial side and crosses over optic nerve
path of the supraorbital artery
will pass anteriorly along the medial border of SR muscle and levator, leaves the orbit through supraorbital notch to face and forehead
what branches off the supraorbital and what does it supply?
- muscular branches: supply SR muscle and levator
- few branches to frontal bone
what does the superior muscular artery branch supply?
- superior oblique
- levator
- superior rectus
what does the inferior muscular artery branch supply?
- inferior rectus
- inferior oblique
- medial rectus
what are the branches that come off the muscular artery branches of the rectus muscles called?
anterior ciliary arteries
where does the anterior ethmoidal artery come off of, and where does it go through the skull?
comes off the medial side and goes into ethmoid bone via the anterior ethmoidal foramen
what does the anterior ethmoidal artery supply?
blood to mucosal tissue in the anterior, medial, and frontal sinuses
where does the small terminal branch of the anterior ethmoid go?
goes through a crack in the bone to the root of the nose to supply skin there
which of the two ethmoidal arteries supplies less tissue?
posterior ethmoidal does not supply as much tissue
what does the posterior ethmoidal artery supply?
the mucosa of the posterior ethmoidal sinus
what do the 2 branches (upper and lower) of the medial palpebral artery supply?
the medial upper and lower eyelid
-they also form palpebral arcades
what is the frontal terminal branch of the ophthalmic artery?
supratrochlear
where does the supratrochlear leave the orbit?
above the medial palpebral ligament
what does the supratrochlear supply?
superficial muscle of the forehead
what is the other terminal branch of the ophthalmic?
dorsal nasal
where does the dorsal nasal branch leave the orbit?
above the medial palpebral ligament
what does the dorsal nasal branch supply?
to the skin at the root of the nose and the lacrimal sac area
what artery is the 1st branch from the ophthalmic?
central retinal artery (CRA)
where does the CRA penetrate?
penetrates into the optic nerve behind the globe about 10-15 mm (on the medial side of the optic nerve)
where does the CRA come into the eye and what path does it take?
comes into posterior segment, to vitreous chamber, and then branches in the nerve fiber layer on the medial side of the optic nerve
where does the CRA supply?
the inner half of the retina
bifurcates into sup. and inf. and so on
how many short posterior ciliary arteries are there?
about 6-12
what is the arrangement and location of the short posterior ciliary arteries?
arranged in a ring around the optic nerve about 3 mm away from the optic nerve
path of the short posterior ciliary arteries
penetrates sclera, forms circle of zinn, goes into perichoroidal space
what does the short posterior ciliary arteries supply?
the posterior half of the eye (will not go forward of the equator
how many of the long posterior ciliary arteries are there?
2
what is the arrangement and location of the long posterior ciliary arteries?
they pierce the sclera about 4mm away from the optic nerve on either side
where does the long posterior ciliary arteries run and supply?
- run in perichoroidal space to the front of the eye
- contribute to major arterial circle of the iris (in ciliary body)
