Retina and optic nerve Flashcards
What does the retina do
Transform light into energy
What is special about the metabolic rate of retina
Most metabolically active tissue in the body
What is the macula
area in primates and birds that has higher concentration of photoreceptors
What does the tapedum do
reflects light back through the retina to give the photoreceptors a second chance to be stimualted
What are rods more important for
dim light
What are cones for
color vision
How many types of cones do most animals have
2
What happens to rodopson in the dark
innactivated
Are neurotransmitters transmitted in the dark
Yes
What happens when rodopson is acted upon by light
activated
What happens to the amount of neurotransmitter released as more light is presented to the rodopson
Inhibited
What’s special about dogs optic nerve mylination
myelinated earlier
Where does the optic nerve exit the oribt
optic foramen
Where do the optic nerves cross
Optic chiasma
What is optic decussation
how much optic nerve is crossed over from one side to the other in the optic chasim
What type of retinal vasculature pattern does the horse have
paurangiotic
What type of retinal vasculatrue does the rabbit have
merangiotc
horizontal/linear pattern
What type of retinal vasculature do crocodiles have
anangiotic
no vessels
What type of retinal vasculatrue do dogs have
holoangiotic
What adaptations does avascular retina have
Thin- to allow O2 diffusion Short outer segments Store glycogen no tapetum no retinal taper may have an extraretinal blood supply
Do animals have more rods or cones than humans
Rods
What benefit is there to having a greater % of rods
Better at seeing at night
What is one of the key features about the retina color
Transparent
