Question

From the textbook, please explain the following: 1.What is Circadian Cycle? 2.What is Meditation? 3.What is Addiction and Psychological Dependence? 4.What is Tolerance and Physiological Dependence? 5.The Stages of Sleep Cycle

Answer 1

Ans.

1.  Circadian rhythms refers to the cycles that inform the body when to sleep, wake, and eat. In other words, it involvesthe biological and psychological processes that oscillate in predictable patterns for each day. The internal clock is influenced by external cues, like sunlight and temperature, which help determine whether one feels energized or exhausted at different times of the day.

2. Meditation is a spiritual practise that involves a conscious attempt to concentrate attention on some object of thought or awareness, in a nonanalytical way. Further, this prevents associative or ruminating thought processes . It usually involves turning the attention inward to the mind itself and focusing on the present moment. Also, meditation can be effectively used for personal development, or to focus one's mind on God.

3. Addiction refers to a biopsychosocial disorder characterized by compulsively seeking to achieve a desired effect, such as intoxication, despite harm and adverse consequences to self and others. Psychological dependence refers to a state involving emotional–motivational withdrawal symptoms, For e.g. anxiety and anhedonia, upon cessation of drug use or certain behaviours. It develops through frequent exposure to a psychoactive substance or behaviour, though behavioural dependence and is less talked about. The specific mechanism involves a neuronal counter-adaption, which could be mediated through changes in neurotransmittor activity or altered receptor expression.

4. Tolerance involves the diminishing effect of a drug resulting from repeated administration at a given dose. Physiological Dependence involves the body telling onself  that it needs the drug to survive. While the person knows that it doesn’t, however the body insists that it must have the substance to live. This has happened because the body had adapted to the influx of the drug’s chemicals. Also, the brain chemistry of the person has changed as the release of certain neurotransmitters may now depend on the presence of the drug. Therefore, until the body gets the substance it will continue to give the withrawl symptoms. Examples of withdrawal symptoms include hand tremors and gastrointestinal issues.

5. During the sleep cycle, there are five stages of sleep These are as follows:-.

Stage 1 of Sleep- It is the lightest stage of sleep. In this, the  EEG brain frequency is slightly slower than during wake time. There is muscle tone present in the skeletal muscles and breathing occurs at a regular rate.

Stage 2 of Sleep- During this stage of sleep, the sleeper is less able to be awakened. And, Stage 2 sleep is characterized by 'saw tooth waves' and sleep spindles.

Stage 3 and 4 of Sleep : Deep Sleep- In these stages, sleep cycle are progressively deeper stages of sleep. These stages of sleep are also called ‘Slow Wave Sleep’ (SWS), or delta sleep. During SWS, the EEG shows a much slower frequency with high amplitude signals. A sleeper in SWS is often difficult to awaken. Research has shown that as humans get older they spend less time in slow wave deep sleep and more time in Stage 2 sleep. In stage three, the greatest arousal thresholds are seen , such as difficulty in awakening, and so on. After being awoken, the person will generally feel quite groggy, and cognitive tests that have been administered after being awoken from the third stage show that for up to half an hour or so, and when compared to awakenings from the other stages, mental performance is moderately impaired. This is a phenomenon known as sleep inertia. When sleep deprivation has occurred there’s generally a sharp rebound of slow-wave sleep, which suggests that there’s a need for slow-wave sleep.

Stage 5 of Sleep (REM Sleep)- In the Stage 5 of the sleep cycle, or REM sleep, sleep is associated with dreaming. It is very different physiologically from the other stages of sleep. The EEG resembles wake time. However, the skeletal muscles are atonic, or without movement. The breathing is more erratic and irregular in this stage of sleep. The heart rate often increases. Also, It is theorized that muscle atonia evolved in order to protect the individual from injury during sleep.