PS101 Chapter Notes - Chapter 5: Nicotine, Harm Reduction, Hypnotic Susceptibility
Document Summary
A periodic, more or less regular fluctuation in a biological system. Rhythms can be synchronized with external (entrainment) or internal cues (endogenous) Biological rhythms influence effectiveness of medication, alertness, job performance. Circadian rhythms occur approximately every 24 hours (e. g. sleep-wake cycle) Removed from cues about 10% of people have clocks running slower and 10% running faster. Increase in accidents at transition to daylight savings time. Controlled by biological clock in suprachiasmatic nucleus (scn) Regulates levels of melatonin secreted by pineal gland. A state in which biological rhythms are not in phase (synchronized) with one another. Changes in your normal routines can cause desynchronization. May also occur in responses to jet lag, rotating shift work, daylight savings time. A disorder in which a person experiences depression during the winter and improvement of mood in the spring. Treatments may involve phototherapy or exposure to fluorescent light. Inconsistent findings with respect to prevalence (2-20%) and effectiveness of treatments.
