question_answer 39)

  George comes on a vacation to India from US. The long journey disturbs his biological system and he suffers from jet lag. What is the cause of his discomfort?

Answer:

                Jet lag is caused by the disruption of the body clock as it is out of synchronisation because of the unfamiliar time zone of the destination. The body experiences different patterns of light and dark conditions than it is normally used to, which disrupts the natural sleep-wake cycle. Melatonin is a hormone that plays a key role in body rhythms and causes jet lag. After the sun sets, eyes perceive darkness and alert the hypothalamus to begin releasing melatonin, which promotes sleep. Conversely, when the eyes perceive sunlight, they tell the hypothalamus to withhold melatonin production. However, the hypothalamus can not readjust its schedule instantly and it may take several days, to overcome this problem.