Chapter17 part3 p.575-577 Flashcards
Where does the ciliary body extend to?
ora serrata
At its periphery, Iris attaches to anterior portion of the _________
ciliary body
What is the serrated anterior edge of retina?
ora serrata
what consists the bulk of the ciliary body?
ciliary muscle
describe ciliary muscle
ring of smooth muscle that projects into the interior of the eye
the epithelium covering the ciliary muscle has numerous folds called what
ciliary processes
What is the ring of fibers that attaches the lens to the ciliary processes?
ciliary zonule/suspensory ligament
what is a vascular layer that separates fibrous layer and the inner layer posterior to the ora serata?
choroid
choroid is overed by
sclera
choroid is attached to the outermost layer of the
retina
what in the choroid deliver oxygen and nutrients to retina?
extensive capillary networks
choroid contains melanocytes- where is is especially numerous?
near the sclera
what are the 2 layers of the retina/inner layer?
thin outer lyaer=pigmented part
thick, inner layer= neural part
what is the role of the pigmented part?
absorb light that passes through the neural part
what prevents the visual”echoes”
the pigmented pat absorbing light
where are the light receptors located?
neural part of retina
what is the role of the supporting cells and neurons in the neural part of retina?
preliminary processing and integration of visual information
Are the 2 layers of retina tightly interconnected?
NO
The pigmented part of retina continues over ciliary body and iris. What about the neural part?
extends only up to ora serrata
The outermost layer of the retina, closest to the pigmented part of retina, contains___________
photoreceptors
2 main types of photoreceptors
rods, cones
Which photoreceptor allows us to see in dimly lit rooms?
rods
What are the 3 types of cones?
red, green, blue
A person who sees 3 primary colors is called
trichromat
________ give us sharper, clearer images
cones
________ requires more intense light
cones
What is the third type of photoreceptor?
intrinsically photosensitive retinal ganglion cell (ipRGC)
What is the photopigment in ipRGC?
melanopsin
What is the function of ipRGC?
They respond to different levels of brightness and influence body’s 24hr circadia rhythm
How are rods and cones distributes across retina?
rods- periphery of retina- highest concentration
cones-concentrated in macula-no rods
Highest concentration of cones occur where?
center of macula- fovea centralis/fovea
Site of sharpest vision
fovea
line drawn from center of object through center of lense to fovea is
visual axis
Rods and cones synapse with about 6 million neurons called ______
bipolar cells
bipolar cells synapse with
ganglion cells
ganglion cells are adjacent to (big structure)
posterior cavity
Describe the connection level of horizontal cells and amacrine cells that facilitate or inhibit communication between photoreceptors and ganglion cells to alter retina sensitivity
horizontal cells: photoreceptors and bipolar cells
amacrine cells: bipolar cells and ganglion cells
Axons from estimated 1 million galnglion cells converge on the ______
optic disc
optic disc is a circular region _____ to the fovea
medial
From the optic disc, the axons go to
diencephalon
Optic disc is (vision)
blind spot
Why don’t you see blind spot in normal vision?
involuntary eye movements keep visual image moving and allow brain to fill in the missing info
Posterior body also contains aqueous humor but ________ takes up most of the volume
vitreous body
Aqueous humor passes from posterior to anterior chamber through _____
pupil
Aqueous humor diffuses across ________
surface of retina
aqueous humor forms by active secretion by epithelial cells of the _______
ciliary process in ciliary body
aqueous humor function
carry nutrient and waste
fluid cushion
fluid pressure stabilize position of ______
retina
Intraocular pressure can be measured in the _________
anterior chamber
Intraocular pressure checked by what method
applanation tonometry
Aqueous humor filters through network of connective tissue located
near the base of iris
After passing through the base of the iris, the aqueous humor enters
scleral venous sinus/canal of Schlemm
Where does aqueous humor go after scleral venous sinus?
collecting channels deliver it to veins in the sclera
Specialized cells embedded in the vitreous body produce ___________ and __________ that account for the gelatinous consistency of this mass
collagen fibers, proteoglycan
When is vitreous body formed?
during development of the eye - not replaced
