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The Autonomic Nervous System

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Sleep is necessary for basic health and survival. It plays a large role in an individual’s mental, emotional, and physiological welfare and functioning. After years of sleep research focusing on sleep-wake cycles, evidence points to the conclusion that sleep deprivation has detrimental consequences, not only on rodents, but humans as well (Cheng et al., 2015). In the past century, the average amount of time that adults sleep has decreased significantly. Consequently, sleep problems have become an epidemic, taking their toll on the health of adult populations in numerous ways. The National Sleep Foundation (NSF) conducted a Gallup Poll in March 2002 in which American lifestyles, sleep habits, and sleep problems were surveyed. The results…show more content…
The autonomic nervous system is concerned with control of involuntary body functions and helps control arterial pressures, heart rate, and body temperature. Within the autonomic nervous system, there are two divisions: the parasympathetic nervous system (PNS) and the sympathetic nervous system (SNS). The SNS controls the “fight or flight” response and helps increase blood pressure, heart rate, and adrenaline (Jansen, Van Nguyen, Karpitskiy, Mettenleiter, Loewy, 1995). Stimulation of the SNS occurs in response to stressful situations, intense exercise, and heart disease (Mullington, Haack, Toth, Serrador, & Meir-Ewert,…show more content…
Monitoring HRV can provide information about the function of the autonomic nervous system. HRV is a non-invasive index of the neural control of the heart (Acharya, Sing, Ping & Chua, 2004). Although it is difficult to establish a particular standard normal heart rate for a given individual, most individuals have a typical range from 60 to 100 beats per minute (Fox et al., 2007). However, the interval between each heartbeat constantly varies. High frequency variability in RR reflects parasympathetic activation, while a slower variability in RR reflects a combination of both parasympathetic and sympathetic modulation along with non-autonomic factors. When interpreting HRV data, there are several components in the power spectrum that can have fluctuating ranges. A power spectrum is a plot of the portion of a signal's power or energy per unit time, falling within given frequency bands. The three major bands of the power spectrum in HRV are high frequency (HF), low frequency (LF), and very low frequency (VLF). A HF peak typically ranges between 0.15 Hz to 0.4 Hz, while a LF peak ranges from 0.06 to 0.15 Hz. A VLF peak is below .05 Hz (Kamath & Fallen, 1993). The LF is associated with blood pressure control and reflects sympathetic activity. The HF is correlated with respiratory sinus arrhythmia and reflects parasympathetic activity
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