True about Fovea is
Ans: b (Contains only cones)Ref: Ganong, 21rd edi., Pg. 152Fovea contains only cones. Cones play a very important role in color vision and rods in nightvision (dim light) Cones are the visual receptors which imparts to the eye, the ability for color visionThere are 3 types of cone pigments: -Cyanolabe -Erythrolabe -Chlorolabe The other visual receptor -rods is mainly for night vision.The pigment present in rods is rhodopsin.Dark adaptationIt is the adjustment of visual mechanism from bright light vision to dim light vision (i.e. switching from cone vision to rod vision)Visual areas in brainPrimary visual cortex area - 17Visual association area - 18,19Frontal eye field - 8Note: Lateral geniculate body is concerned with vision.Medial geniculate body is concerned with hearing.(Remember- L for light and M for music)
Contains only rods
Contains only cones
Situated above optic disc
Contains both rodes & cons
Nervous System