Describe the following disorders and list the causes and/or predisposing factors for each: night ...

ANSWER:
Night terror: A sleep disorder in which the sleeper wakes suddenly in great distress, but without experiencing the imagery of a nightmare. There is usually no memory of the night terror the next day. In night terrors, the usually smooth transition from Stage 4 N-REM sleep upward into REM goes awry. There may be a genetic predisposition to night terrors, as 80 of people with this condition report a family history for the behavior.

Onset insomnia: A sleep disorder characterized by an inability to initiate normal sleep. In cases of onset insomnia, a person will lie in bed for what seems to be a very long period but be unable to go to sleep. Stress and anxiety are frequent causes of this type of insomnia.

Maintenance insomnia: A sleep disorder characterized by an inability to maintain normal sleep. Maintenance insomnia occurs when sleep is frequently interrupted or early waking occurs. These cases typically result from stress, substance use, or psychological disorders.

Narcolepsy: A sleep disorder characterized by the intrusion of REM phenomena into wakefulness, sometimes referred to as sleep attacks. Attacks are often instigated by strong emotions. In many cases, narcolepsy appears to be a genetically determined disturbance in the control of REM sleep. The gene suspected of abnormalities in narcolepsy affects the activity of neurotransmitters known as orexins. Cells in the hypothalamus that normally secrete orexins are missing or damaged in the brains of patients with narcolepsy.

Cataplexy: A disorder, which occurs when the muscle paralysis normally associated with REM sleep occurs during wakefulness without any loss of consciousness. Having sex is a common emotional trigger for the disorder. Many patients with narcolepsy also experience sleep paralysis, or muscle paralysis that either precedes actual sleep or lingers once the person has awakened. Although upsetting, this paralysis is easy to resolve. Simply touching the person is enough to end the paralysis.