BIOL 1000 Lecture Notes - Lecture 2: Mota, Motb, Pineal Gland
Document Summary
Role of light in ecology & behavior **self review** Many physiological & behavioral responses are operated in a 24-hr cycle synchronized with our day & night cycles. *circa = around, diem=day circadian rhythms (fig 1-23, pg 14) Ex: sleep habit, blood pressure, hormone release, body temp --internal biological clock controls all these resetting the circadian rhythm (fig 1. 24) Light gives signal to retina then to scn then to pineal gland then melatonin, which regulates the pbc. Peripheral biological clock (pbc(cid:524) doesn"t receive signals from light. When u don"t have light, the pineal gland will make melatonin and it will be at its. Pbc doesn"t get signal from light, the scn does (cid:523)and then this regulates the pbc(cid:524) peak. Signals pbc which regulates body temp, blood pressure, hormones. Scn is regulated by melatonin what happens when external cues don"t match the circadian rhythm? (fig 1. 25) Sometimes the external clock doesn"t sync with the internal (cid:523)ex: jet lag)
