Glossary of Neuro - Visual System
Other Decks By This User
- What is emmetropia?
- normal vision
- What is farsightedness called?
- Where does the image converge in hyperopia? Why?
- behind the retina, because eyeball is too short
- Where does the image converge in myopia? Why?
- in front of the retina, because eyeball is too long
- What is nearsightedness called?
- Cell types in the retina? (from outer to inner)
- rods/cones -> (w/modulation by horizontal cells) -> bipolar cells -> (w/modification by amacrine cells) -> ganglion cells -> converge as optic nerve
- How is the light signal transduced into an electrical signal?
- light -> absorbed by rhodopsin in rods/cones -> conformations shift activates G protein cascade -> Na channels CLOSE -> HYPERPOLARIZATION of photoreceptor cell -> STOPS releasing NT
- Which retinal cells fire action potentials?
- ganglion cells only
- What 4 places do ganglion cells project to?
- LGN (majority), suprachiasmatic nucleus of hypothal (circadian rhythms), superior colliculus (saccadic eye mvts), pretectal area (Ed-Westphal/pupillary light reflex)
- Symptoms of 3rd nerve palsy?
- resting "down and out", droopy eyelid, external strabismus (can't focus), mydriasis (dilated pupil), loss of accomodation
- Symptoms of trochlear nerve damage?
- vertical diplopia, difficulty walking down stairs, compensates by tucking chin and looking up slightly, and tilting head away from lesion (to compensate for loss of intorsion)
- Symptoms of abducens nerve damage?
- horizontal diplopia on attempted gaze toward lesioned side
- What is the function of the vestibulo-ocular reflex?
- keep image stationary on retina during head mvts
- What is the function of the optokinetic reflex?
- keep image stationary on retina during visual field motion
- What types of eye movements are used to capture and keep particular stimuli on fovea?
- Saccades, smooth pursuit, fixation
You must Login or Register to add cards