BIOL 031 Lecture Notes - Lecture 21: Cochlea, Color Vision, Retina
Document Summary
Vision is best at fovea centralis: here, other layers of the retina are pushed aside, so light falls directly on a group of cones, only works in good light. Eye movements continually shift parts of the visual field onto the fovea. Convergence of lots of rods onto a single ganglion cell increases light sensitivity. Color blindness- genes for color vision on x chromosome. Color blindness- color vision product of only two or less types of cones. Vision- visual information is separated before reaching visual cortex. Thus, left side of visual field of projected to right half and vice versa. Distinguishing pitch is possible because: different frequencies stimulate different regions of the basilar membrane (low frequencies at the end) Ciliary muscle contracts to make the lens thicker (contract) Regulate organic metabolism and h2o and electrolyte balance. Induce adaptive changes to help body cope with stressful situations.