17 - 3 Flashcards
Sleep occurs in two main phases: rapid eye movement (REM) sleep and non–rapid eye movement (NREM) sleep, which constitutes three stages.
A sleeper goes through several cycles of NREM and REM sleep each night. Each stage is characterized by different patterns of electrical brain activity as measured by the electroencephalogram (EEG) and accomplishes different functions.
Circadian rhythm is the sleep and wake pattern coordinated by the brain’s master internal clock, the suprachiasmatic nucleus (SCN).
The SCN sets and controls—synchronizes—the sleep–wake cycle of the brain and of every cell in every organ of the body.
The rhythm can be disrupted by jet lag and irregular sleep practices, as well as by substances such as caffeine and alcohol.
Our circadian rhythm is most strongly influenced by light exposure, as well as by activity, exercise, and eating—zeitgabers that can reset our wake–sleep clocks
Good light exposure in the morning and daytime and reduced exposure to light at night strengthen the rhythmic effects.
Sleep rhythms and needs change with aging. In the teen years, a delayed sleep phase develops, and other circadian rhythms change.
Adults consistently need seven to nine hours of sleep per night. As we age, however, the amount of overall sleep and the amount of deep sleep we get diminish.
Sleep is important for mental health, mood, creativity and learning, and physical health.
Sleep promotes longevity and diminishes the risk for the emergence of major diseases.
Poor-quality or insufficient sleep has been associated with a number of health problems and impairments—
heart disease, high blood pressure, depression, earlier death, increased risk for dementia, weight gain, poorer glucose control, increased risk for accidents, reduced motivation and attention, and increased irritability or hyperactivity.
Chronic sleep disorders are medical conditions that prevent people from sleeping well.
Very common sleep disorders are chronic insomnia, trouble falling asleep or staying asleep; restless leg syndrome; and sleep apnea, repeated stops in breathing for short periods—frequently 20 to 40 seconds—while asleep. They can all be treated, some through lifestyle changes.
Sleep disrupters are specific factors that interfere with the ability to fall or stay asleep that can usually be corrected if they are targeted specifically.
These include caffeine, reflux, nasal congestion, cough, urination, anxiety or stress, pain, environmental factors such as room temperature and lighting, electronic devices, alcohol, tobacco, and medications, among others.
