PSYA01H3 Lecture Notes - Lecture 5: Non-Rapid Eye Movement Sleep, Delta Wave, Sleep Spindle
Document Summary
Organisms have developed biological rhythms which they have adapted in relation to their environment. Infradian rhythm means that it occurs over a time period which is not longer than a day. Circannual rhythm means that a cycle happens during a year. Most biological rhythms occur over less than a month: i. e. heart rate, urination etc. Circadian rhythms are cycles that usually occur daily and greatly influence biological and behavioural processes- they relate to being asleep and awake during specific times of the day. These rhythms are often influenced by daylight which interacts with out nervous and endocrine systems. Our eyes allow signals to be sent to the scn of the hypothalamus. The scn in turn forwards these signals to the pineal gland which releases the hormone melatonin which increases in concentration during nighttime and reduced levels of light. There are two possible explanations for these 24 hour rhythms:
