Humans spend approximately one-third of their lives sleeping, which means that by the time you reach 15 years old, you will have slept for about 5 years! However, the question remains: why do we do it? Sleep has long been a puzzle for people, leading scientists to explore its mysteries. They have found that during sleep, our brains and bodies do not simply shut down; instead, complex processes unfold.
What causes sleepiness? It's caused by our biological clock releasing a special chemical signal at the same time daily, signaling it''s time to wind down. The feeling of heaviness comes from the buildup of old nerve messenger chemicals. When the message gets too much, the brain senses that it's time to sleep. During sleep, the body breaks down and clears away these old messengers, preparing for a fresh start.
As you slip into sleep, your heart and breathing slow down, and your brain ignores the most sounds and surroundings around you. Despite appearances, your brain remains active during sleep, performing essential tasks. Throughout the night, you cycle through light, deep, and REM(rapid eye movement) sleep stages every 90 minutes. Early on, slow-wave sleep is the primary stage, aiding in brain cleaning, while towards morning,REM sleep increases, leading to vivid dreams. During sleep, your body repairs and grows, creating new skin, muscle, and other tissues with released chemicals. It's also a time for hormone(荷尔蒙)production, aiding growth, and boosting the immune(免疫)system to fight infections.
Scientists still have many questions about sleep, such as why some people need more sleep than others and how certain animals can function with less sleep. They aim to find ways to improve sleep quality. However, one thing is clear: getting enough sleep is vital for health and intelligence. Think of sleep as a free magic potion that strengthens you, aids growth, boosts immunity, and enhances intelligence, happiness, and creativity. Simply lie down and rest to enjoy these benefits.