Flashcards in 5.5 Visual Pathways Deck (24):
What layer of the retina are the rods located?
What layer of the retina are the cones located in?
macula region of the retina (central)
What is the center of the macula called that only contains cones?
What spot in the retina contains no receptors and is considered the blind spot; where optic nerve enters eye?
What is the yellowish oval area lateral to optic dis with a central depressed spot?
What is the most acute area of vision?
Which fibers cross in the optic chiasm?
nasal retinal fibers cross to contralateral side and head to contralateral optic tract
What structure forms posterior to the optic chiasm?
What structure is superior to the optic chiasm?
Where does the optic tract project to and where do most fibers synapse?
thalamus (lateral geniculate nucleus)
What are the fibers exiting the LGN known as?
Optic radiations that extend into the visual cortex
Where is the primary visual cortex located?
occipital lobe (Brodmann area 17)
Where do the superior optic radiations terminate?
Where do the inferior optic radiations terminate?
Which structure do the fibers pass through from the primary visual cortex to in the occipital lobe?
visual association cortex (Brodmann area 19)
The visual association cortex receives visual feedback from the primary visual cortex and projects to the .... in the midbrain.
The pretectal nucleus projects bilaterally to what?
Edinger Westphal nucleus
The Edinger Westphal nucleus gives rise to preganglion parasympathetic axons that travel via CN III to what to synapse?
Postganglionic parasympathetic innervation from CN III to what?
sphincter pupillae to constrict pupil and ciliaris muscle to thicken lens
What visual defect is caused by a pituitary adenoma?
bitemporal hemianopia (loss of half the visual field on the temporal side)
What results from transection of left optic tract?
Right hemianopia (loss of vision from nasal field of left eye and temporal field of right eye)
In temporal lobe lesions, Meyer's loop may be affected, giving rise to visual deficit known as?
contralateral upper quadrantopia
What results from transection of cuneus gyrus?
contralateral lower quadrantopia