While sleeping

What you need to know what happens to your body while sleeping. 
Sleep consists of two radically different physiological states. There is rapid eye movement sleep (REM) and non-rapid eye movement sleep (NREM). The sleep stages seem to have different functions, but why we sleep is still not completely understood. Babies spend half of their sleep in REM, but this drops to a quarter by the age of two. It is therefore thought that REM sleep is particularly vital for the developing brain. In NREM sleep, brain activity slows and a person woken at this stage may feel groggy.

 

1.While sleeping your Pituitary gland which is a tiny organ, the size of a pea, found at the base of the brain, secretes  hormones.

While sleeping During non-REM sleep, the pituitary gland produces growth hormone and secretes prolactin. This counteracts dopamine, to lower general arousal levels. The pituitary gland  is part of the endocrine system and produces critical hormones, which are chemical substances that control various bodily functions.

2. While sleeping in your mouth the production of saliva decrees.

While sleeping  

As you fall asleep, your body signals the glands in your mouth that produce saliva to decrease production. If your saliva production didn’t decrease while you slept, you would be constantly swallowing, which would interrupt your sleep. Also, you would lose a lot of water during your sleep if your saliva production didn’t decrease. Five per cent of adults also grind their teeth at night, mostly during the early stages of sleep.

3. While sleeping your lungs go through various ventilation cycles.

While sleeping During the non-rapid eye movement sleep (NREM), the ventilation in the body decreases steadily to about 15 percent of what is normal for a healthy awake person. The throat muscles relax so your airway narrows when inhaling. This can cause snoring, or temporarily halt your breathing for a few seconds (sleep apnoea). The best way to protect your lungs while you sleep is to keep them healthy while you are awake.
4.While sleeping your heart is beating more forcefully, irregularly or faster than usual.
While sleeping Sleep is essential for a healthy heart. People who don't sleep enough are at higher risk for cardiovascular disease and coronary heart disease—regardless of age, weight, smoking and exercise habits. Getting enough good quality sleep is important if you want to lower you risk of these conditions. It's not completely clear why less sleep is detrimental to heart health, but researchers understand that sleeping too little causes disruptions in underlying health conditions and biological processes like glucose metabolism, blood pressure, and inflammation.
5. While sleeping your limbs are paralysed.
While sleeping The extra blood swells your arms and legs slightly. Muscles are paralysed while dreaming, but between dreams you change sleeping position 35 times a night. The tingling or "pins and needles" feeling that people experience happens as the nerves are regaining function. Your foot or limbs are "waking up." In medical terms, this is known as paresthesia. The discomfort, which is sometimes painful, generally causes you to change your position.

6.While sleeping your bladder muscle cells are often regulated by circadian rhythms. While sleeping

Vasopressin hormone levels rise. This reduces the amount of urine collected in the bladder to between half and a third of normal daytime levels. If you frequently lose sleep over urinary incontinence, you’re not alone: According to the National Association for Continence, at least two percent of adults lack control over their bladders while sleeping, and more than a third who wake up to go the bathroom do so at least twice a night.