exam #1 sleep Flashcards
inactivity theory:
explains that inactivity at night or day is an adaptation for survival at a time of daily vulnerability through low visibility or oppressive temperature (2). For example, animals may sleep through periods of time during which they are most often preyed upon
Energy Conservation theory
proposes reduction of energy demand and expenditure is aided by a period of inactivity such as sleep. In natural selection, competition for and efficient use of energy resources is vital—if a species uses its given energy resources even slightly more effectively, it would have an advantage over similar species
Restorative theory
sleep restores, repairs, and rejuvenates the body. After all, many major restorative functions—such as muscle growth, tissue repair, protein synthesis, and growth hormone release occur mostly or entirely during sleep
brain plasticity theory
sleep is correlated to changes in structure and organization of the brain. In particular, sleep has a critical role in brain development of infants and young children (2). Sleep also improves learning ability and task performance in adults
NREM
Non-Rapid Eye Movement (NREM) Sleep
Sleep typically begins with NREM
As NREM sleep progresses, the brain becomes less responsive to external stimuli
4 stages
N1: typically lasts 1-7 mins (“nodding off”) N2: 10-25 mins
N3: transitional period between light sleep and deep sleep
N4: deep sleep
REM
Rapid Eye Movement (REM) Sleep
Active sleep”
physiological change in brain activity
This chart shows the brain waves of a young adult recorded by an electroencephalogram (EEG) during a night’s sleep. As the adult passes into deeper stages of sleep, the brain waves slow down and become larger. Throughout the night, the individual goes through these stages multiple times, with brief periods of REM sleep, during which the EEG is similar to wakefulnessResearchers found that each night, over the course of the first hour or so of sleep, the brain progresses through a series of stages during which brain waves slow down
physiological change in Cardiovascular
heart rate slows during deep sleep with slow brian waves. During REM Heart rate, blood pressure, and body temperature become much more variable
physiological change in Sympathetic nerve activity
during REM muscle paralyses except for respiratory and eyes
physiological change in Muscle tone
relaxation during deep sleep with slow brian waves but during REM muscle paralyses except for respiratory and eyes
physiological change in Respiration
Mean inspiratory flow rate (VT/Ti), an index of inspiratory drive, was significantly lower in REM sleep than during wakefulness or non-REM sleep. Thus ventilation falls during sleep, the greatest reduction occurring during REM sleep, when there is a parallel reduction in inspiratory drive
physiological change in Body temp
temp falls during deep sleep with slow brian waves.During REM Heart rate, blood pressure, and body temperature become much more variable
how does age affect sleep?
Newborns (1 to 2 months) – 10.5 to 18 hours
how does alcohol affect sleep?
alcohol decreases the amount of REM sleep approximately 30min less for every two drinks
how does napping affect sleep?
napping reduces cortisol and promotes huh but naps should only be 20-30min long
The effect of light
It does so both directly, by making it difficult for people to fall asleep, and indirectly, by influencing the timing of our internal clock and thereby affecting our preferred time to sleep
Jet lag and shift work
Individuals who travel across time zones or work the night shift typically have two symptoms. One is insomnia when they are trying to sleep outside of their internal phase, and the other is excessive sleepiness during the time when their internal clock says that they should be asleep
Pain, anxiety and other medical conditions
Like many other sleep disruptions, pain and discomfort tend to limit the depth of sleep and allow only brief episodes of sleep between awakenings. tend to find it more difficult to fall asleep, and when they do, sleep tends to be light and includes more REM sleep and less deep sleep.
sleep and disease risk?
Obesity
nsulin Resistance - Diabetes
cortisol
stress hormone related to weight gain……unctions are to increase blood sugar through gluconeogenesis; suppress the immune system; and aid in fat, protein and carbohydrate metabolism
melatonin
Melatonin is a hormone made by the pineal gland camera, a small gland in the brain. Melatonin helps control your sleep and wake cycles. Very small amounts of it are found in foods such as meats, grains, fruits, and vegetables. You can also buy it as a supplement
circadian rhythm
is any biological process that displays an endogenous, entrainable oscillation of about 24 hours
how is performance affected by sleep?
preventable accidents
reventable accidents
what is your amount of sleep determined by?
Determined by genetics and age
