Flashcards
vision;; the eye
Cards in this deck (30)
- 1liquid the eye is surrounded byaqueous and vitreous liquid
- 2ciliary muscleadjusts lens
- 3accomodation range- reflex of the eye when focusing
- NEAR VISION
-Ciliary muscle CONTRACT
- Thicker lens
- suspensory ligaments SLACK - 4unaccomodated rangeCM relaxes
- thin lens
SL tense - 5can the retina be seen through the a device?Yes, using the ophthalmoscope we can see the retina due to light receptors (ie. bc there isl ight there)
- 6myopiashort-sightedness;light rays focus on front of retina
- 7hyperopiahyper(long)
- farsightedness; Light rays focus beyond the retina (picture the digram) - 8what are the 5 classes of neurons?photoreceptors, bipolar cells, ganglion cells; horizontal cells and the amacrine cells
- 9what is the quicket route to the brain from the retina (neuronal)PR > BC > GC> optic nerve (the brain)
- 103 layers of the retinal nucleus: inner nucleus layers;BCs, HCs, ACs nuclei
- 113 layers of the retinal nucleus:GC layerretinal nucleus layer; gc layer has gc nuclei
- 123 layers of the retinal nucleus: outernucleus layersPRs nuclei
- 13what are rods?PRs sensitive to light and dark colours.
good for darkness. - 14what are cones?PRs, that are colour sensitive. good in light area.
- light causes a great change ie. hyperpolarisation: voltage decreases. - 15gmp-gated channels are activators for what?Na+ channels OPEN, more NA and CA in neuron
- 16what happens to rods when they are exposed to light?light exposure decudes the cGMP
why? bc amt of light is depedent on the amt of agtes opened. - 17when are PRs active?active? when they reach threshold.
- 18active threshold of cones?- when in the dark, it is inactive.
- only active when there is light. - 19rods also do what?these photoreceptors also detect movement
- 20there are more cones in this area of the macular; why?there is a higher amt of cones for focusing (high acuity) ie. for reading.
- higher spatail freq
- higher resolution - 21the optic discnicknamed the 'the blind spot' bc we cannot see anything there.
- why? no PRs - 22how many photopigments to rods have?1 pp
- 23there are 3 different cones; each with what to allow them to work?3 diff cones for 3 diff pps /wavelengths
these are long, medium and short (RBG pps) - 24protanopialoss of LONG wavelength (red pps)
- 25deutenopialoss of medium w/l (blue pps)
- 26on-center GCactivate on center when there is light
- 27off-center GCactivate OFF center whenb it is dark
- 28what NT is released in cones?GLUTAMANE
- 29what happens to more release of glutamane?hits ganglion cells and fires more rapidly.
- 30—