The SCN is known as your biological clock because it facilitates circadian rhythms based on light cues from retinal cells. Most humans establish their circadian rhythm during the first four months of their lives. Other functions your circadian rhythms regulate include appetite and digestion, body temperature, and hormonal production. Many associate circadian rhythm with sleep, but the term applies to any physical, mental, or behavioral function that follows a 24-hour timetable based on natural light and darkness. Cells located in the brain stem and hypothalamus also produce GABA, a chemical that decreases arousal in these areas of the brain.Ĭircadian Rhythm and Sleep-wake Homeostasis Once these signals are received, the pineal gland secretes melatonin to help you feel tired and ready for bed. The SCN also receives signals from the retinas as evening arrives and natural light begins to fade. These processes keep you awake and alert. During the daytime when your eyes are exposed to natural light, retinal cells send signals to the SCN, which in turn signals other areas of the brain. These components work together to coordinate your sleep-wake cycle. Pineal gland: Part of the endocrine system, the pineal gland produces melatonin, a hormone that promotes feelings of sleepiness.Cerebral cortex: Also known as gray matter, the cerebral cortex is a thin layer that covers the brain and helps process thoughts and memories.Thalamus: The thalamus is a cluster of nuclei that relay sensory signals between other parts of the brain.Its structures include the midbrain, pons, and medulla. Brain stem: The brain stem is the smallest of your brain’s three major components and is located near the spinal cord.Retinas: Located at the back of each eyeball, retinas are layers of tissue that help focus images transmitted through your eyes’ lenses.Suprachiasmatic nucleus (SCN): The SCN is a cluster of nerve cells located in the hypothalamus that receives and transmits signals about light and darkness exposure, essentially forming your internal clock. Hypothalamus: This region of the brain coordinates the production of hormones that guide sleep, body temperature, hunger, mood, and other bodily functions.Holistically speaking, your entire body is integral to facilitating sleep-related processes, but key players in your sleep cycle include: While your body is not as active during sleep as it is when you are awake, parts of your brain continue to operate and communicate with one another. A common myth about sleep is that the body completely shuts down between the time you fall asleep and wake up in the morning.
0 Comments
Leave a Reply. |