What physiological changes occur during NREM sleep?

During NREM sleep, the body experiences a range of physiological changes that promote restoration and recovery. One of the hallmark features of NREM sleep is the decrease in heart rate and blood pressure. This reduction helps facilitate a more relaxed state, allowing the body to conserve energy and repair tissues.

As a person transitions through the different stages of NREM sleep, particularly during deep sleep (slow-wave sleep), there is marked parasympathetic nervous system activity which slows the heart rate and lowers blood pressure significantly. This is in contrast to the physiological state during wakefulness or REM sleep, where heart rate and blood pressure can increase.

Additionally, NREM sleep is characterized by consistent breathing patterns, unlike the irregular breathing that can occur during REM sleep. Furthermore, muscle tone generally decreases during NREM, promoting relaxation and reducing muscle tension. Overall, these changes promote restorative processes such as growth and healing, making NREM sleep crucial for overall health and functioning.