Vision Flashcards
Phototransduction takes place on _____ and _____ whereas the nerve impulse is sent on __________
Rods and cones Ganglion cells (projection neurons)
Where are cones concentrated?
in the fovea
*cones see color
Where are Rods least concentrated?
in the fovea (more dense in the peripheral regions where cones are less prevalent)
*rods see black and white
Temporal visual fields _________ whereas nasal visual fields remain _____________
cross (decussate), ipsilateral
Input is from an individual eye where?
prior to chiasm
input from both eyes together is where?
after the chiasm
The top portion of the occipital lobe has vision to see the __________ whereas the lower portion is to see _________
ground, sky
What landmark separates the upper and lower fields in the occipital lobe?
Calcarine sulcus
The retina receives blood supply from what?
Ophthalmic artery (ciliary arteries, central retinal artery)
The parietal optic radiations receive blood from what?
middle cerebral artery
The LGN and optic tract receive blood from where?
Anterior choroidal artery (branch of middle cerebral)
The calcarine cortex receives blood from where?
posterior cerebral artery
What three things does CN III do for the near response?
1-Adduct both eyes (medial rectus muscles)
2-Constrict both pupils to focus light
3-Constrict ciliary muscles, causing lens to thicken and refract light more)
The pupillary dilation response is caused by what system?
Sympathetic pathways
A lesion of central or peripheral sympathetic nervous system that causes ptosis, miosis and anhydrosis is called what
Horner’s Syndrome
