Epinephrine Levels: Sheila's Lack Of Sleep

Sleep plays an essential role in maintaining good health and wellbeing throughout one’s life, so what happens both physically and mentally when one does not get enough sleep? As described in the introduction to chapter nine, Sheila decides to travel from Boston to Paris and wants to sleep on the flight in order to maximize her time awake, and thus her time to sight see, while in France. Unfortunately, due to the vibration of the plane, the loud family of travellers sitting behind her, and other extraneous stimuli, she was unable to fall asleep during the flight. When Sheila lands in Paris, she appears to be more excited than tired because the stress of travelling and not sleeping causes her epinephrine levels spike. This heightened epinephrine production results in a fight-or-flight response, which corresponds to increased blood pressure and focus, and could be mistaken for feeling awake. As Sheila wandered through the Louvre and explored Paris, however, her epinephrine levels slowly fell and eventually got so low that that she crashed for over ten hours.

Although Sheila’s epinephrine levels can account for much of her behavior, her lack of sleep can also be attributed to the jet lag common on trans-Atlantic flights.

When travelling through multiple time zones (the time difference from Boston to Paris is six hours), one’s circadian rhythm can be thrown off. This change in body clock regulation is largely due to the fluctuations in light and dark exposure, deregulation of body temperature, and change in daily activity experienced while in the air. These disruptions alter the activity of the suprachiasmatic nucleus of the hypothalamus and cause one to be more drowsy and fatigued the following day than they would be if not

travelling.
Although it has long been shown that the suprachiasmatic nucleus plays a critical role in circadian rhythm, it has more recently been shown to be important in dream formation. For decades, Freud and Jung asserted that dreams were messages of our sub-conscious; however, psychologists now have proof of a more biological standing and significance. As an individual enters rapid eye-movement sleep (REM sleep), their brain stem is stimulated and their visual perceptions are activated. Without external stimulation, however, the brain randomly pieces together memory fragments to form one story (aka the dream). In addition, the caution and judgment areas of the prefrontal cortex are inhibited while dreaming and account for the often outrageous and impossible content that dreams are known for. Although dreaming only occurs during one stage of the sleep cycle, it is important to note that one will spend approximately one quarter of the night dreaming, and they will have four to six different dreams during that period.
As shown in Sheila’s story, not getting enough sleep can be extremely detrimental to both one’s mental and physical functioning, but can oversleeping cause the same effects? In short, yes and no. Recent studies have shown that those that consistently receive over nine hours of sleep have an increased risk for heart disease, diabetes, and overall death, at rates similar to those of individual’s that consistently under sleep. Over sleepers are more prone to depression and are more likely to be of a lower socioeconomic status compared to their under sleeping counterparts; however, they experience less cognitive deficiencies such as lack of attention, irritability, and limited memory recall.