PSL300H1 Lecture Notes - Lecture 27: Ventrolateral Preoptic Nucleus, Circadian Rhythm, Circadian Clock
Document Summary
Circadian rhythm is a 24-h oscillation of a physiological regulation (governed by neuronal oscillator) Falls into synchronism to exact day-night cycle by retinal input from ganglion cells with melanopsin: melanopsin the most important/peek absorbance in blue-green spectrum, excited by it. Red light is not absorbed ignored. This is the master regulator of circadian rhythm. Sits on top of the optic chiasm the input to suprachiamatic nucleus is whether it is light (daytime: pretectal area through sympathetic efferents or not. Projects to the superior cervical ganglion and ends up in the pineal body (nucleus which sits right in the middle of it) Pineal body important for releasing melatonin. Circadian modulation a lot of these parameters are dependent on circadian rhythm. Hormone synthesis and secretion (peak in the morning) Body temperature (lowest at night, highest during day) Mood (changes depending on the time of day) Sleep-wake cycle (shows oscillation of 24h period)
