# Sensory systems 6 - Non visual photoreceptors

Tell time of day, predict the changes in the environment. They are for survival purposes, circadian rhythms
Click the card to flip 👆
1 / 18
Terms in this set (18)
study done in the 1800s. The rotation study, the plant detects light at daytime and opens it's leave. but even when dark and left in cupboard they would still open their leaves at a certain time. This showed there must be another function for keeping in time and in tune not just daylight as the only mechanism. - important findings in terms of circadian rhythms
Study of mammals and circadian rhythms. Looked at nocturnal animals that run on a wheel at night. always has separate inactive and active zones. They would always get up at a certain time, when lights were off at 8pm. When they moved the around the mouse would adjust to waking when the lights went off. This showed that they had a endogenous timing mechanism which was synchronised to the light dark timing.
The activation of rods and cones receptors at different times. How activated each set is. Rods more sensitive to different light intensities - depolarise when light, hyperpolarised in the dark. Cones work better in the dark, they have to adjust sensitivities during the day - photoreceptor adaptation. High intensity changes across dawn and dusk.