vision Flashcards
what are some layers and cells of retina?
ganglion cells: magnocellular and parvocellular. Then photoreceptors -rods and cones. then in between interneurones-bipolar, amacrine and horizontal cells. lastly pigment epithelium.
true/false, fovea centralis and macula lutea are highest in optic disk.
false, optic disk is the blind spot. they are in central retina.
why do we have high accuracy in fovea centralis and macular lutea?
due to the full transmission that occurs as light directly hits them. also each photoreceptor cell communicates with one cell, unlike periphery- one talks to many.
what is the role of pigment apithelium?
phagocytosis of shedding disks of photoreceptors.
what happens in macular degeneration?
the pigment epithelium undergoes death/not ganglion cells-phagocytosis decreases-photoreceptors degenerate.
What happens with retinal detachment?
occurs due trauma, affecting the pigment and photoreceptors.
where do the ganglion cell fibres cross in the retina?
in the fovea- the nasal side.
what are the functions of lateral geniculate nucleus?
organises function-magno and parvo. organises topography-contralateral, peripheral visual field, etc. lastly, which eye (laterality)-nasal or temporal retina.
what are the structures involved in unconscious vision?
suprachiasmatic n-time, pre-tectum- papillary reflex CN2/3, superior col-visual reflex, pulvinar-higher order attention, recog, V2-V5, orientation, colour, motion.
where do suprachiasmatic, pretectum and superior col and pulvinar project?
Schi: pineal gland-melatonin, pretectum to Edinger Westphal-constriction of iris, SuCol- gets help ftom pulvinar to follow things and then projects to parietal to recognise that thing.
