Water and the Human Body.

 Water Properties Information

Up to 60% of the human adult body is water.

 The brain and heart are composed of 73% water,

 and the lungs are about 83% water. 

The skin contains 64% water, 

muscles and kidneys are 79% water, 

and even the bones are watery: 31% water. 

Each day, humans must consume a certain amount of water to survive. 

Specifically,  32.43 milliliters of water is required for every 1 kilogram of body weight, per 24 hours.  Under normal resting condition.  

More water is required when weather is hotter or colder and during more energy activities are involved,  such as exercising, staying awake beyond the normal hours ( graveyard shift work), and thinking solutions for problems.

With water making up about 60% of your body weight, it's no surprise what staying well hydrated correctly do for you. 

Here are just a few examples of the ways water works in your body: 

Regulates body temperature.

 Moistens tissues in the eyes, nose and mouth.

 Protects body organs and tissues.

 Carries nutrients and oxygen to cells.

 Lubricates joints. 

The Functions of Water In The Body:

 Transports nutrients through the body.

 Once a substance is dissolved in water, water becomes vital for transporting it throughout the body. 

Blood - which is 83% water - transports oxygen, CO2, nutrients, waste products and more from cell to cell. 

Urine is also mostly water.

As water is the most plentiful molecule inside a cell, it comprises much of the body weight in humans, approximately 75% of body mass in infants and 55% of the mass in the elderly.

 However, as humans are constantly losing water, maintaining water homeostasis is vital.

What is water homeostasis?

Whilst water in the human body is found in plasma and the intestine, the overwhelming majority is found within cells. As humans continuously lose water through urine and feces, perspiration, and respiration, a finely balanced and sensitive network of physiological controls is necessary to maintain water levels. This is body water homeostasis, which is maintained by stimulating fluid intake by thirst.

Thirst is a biological instinct, mediated by sensory receptors called osmoreceptors. These receptors are located in the hypothalamus and detect changes in blood plasma. When they detect low blood volume, they signal to the hypothalamus which in turn generates the sensation of thirst. This homeostatic control mechanism ensures a balance between fluid loss and fluid intake.

Dehydration

The term dehydration refers both to the process of losing body water, and the deviation from an ideal hydrated state. It occurs when lost fluids are not replaced, prohibiting the body from carrying out normal functions.

Although dehydration can affect anyone, it is particularly dangerous in young children who can become severely dehydrated following diarrhea and vomiting, and older adults who have a lower volume of water in the body. This means even minor illnesses or chronic disorders can result in dehydration in the elderly. Whilst mild to moderate dehydration can be reversed with fluid intake, severe dehydration requires medical treatment.

Dehydration can lead to serious health complications including:

• Heat injury: Caused when fluid loss through perspiration or exercise is not replaced, heat injuries range from mild heat cramps to heat exhaustion or life-threatening heat stroke.

• Seizures: A state of dehydration is also associated with electrolyte abnormalities. Electrolytes including potassium and sodium assist in electrical signaling between cells. Electrolyte abnormality can cause misfiring between cells, leading to involuntary muscle contractions or loss of consciousness. People with pre-existing seizure disorders such as epilepsy are especially at risk.

• Urinary and kidney problems: Severe or repeated mild bouts of dehydration cause a build-up of wastes and acids in the body, which in turn exposes the kidneys to an excess of myoglobin. The kidneys are responsible for removing myoglobin from the blood, but excess may cause kidney damage and kidney failure.

• Hypovolemic shock: A life-threatening condition that results from losing more than 20% of the body’s blood or fluid supply. The severe loss affects the heart’s ability to pump sufficient blood around the body, leading to organ damage and death. 

Hydration : Means drinking correct amount of plain water regularly  throughout waking hours for personal body weight, daily.  And enough sodium and other essential minerals intake in one's diet. 

Ensuring adequate fluid intake is critical for many functions. These include:

•Body temperature regulation: Humans are designed to regulate body temperature, particularly when exposed to hot conditions such as a hot climate or during exercise. Losing water through the skin (perspiration) cools the body and helps to maintain homeostatic temperature. Without replacing the lost fluid, however, body temperature will rapidly increase.

• Removing bodily waste: Metabolic processes generate waste products that would otherwise harm the body if retained. Water acts as a solvent for waste products, dissolving them and allowing them to pass out of the body via urine and perspiration.

• Digestive processes: Water taken before, during, and after food aids effective digestion by working with digestive fluids to break down food, enhancing transit through the digestive system. It also aids the absorption of nutrients.

Urine Test.

Signs of adequate hydration are visible in urine. 

The chemical urobilin is responsible for the yellow pigmentation of urine and is diluted by fluids. 

Therefore, the better hydrated a person is, the clearer their urine appears. 

Dark-colored and strong-smelling urine is a clear sign of inadequate hydration.

水属性信息

 人体高达 60% 的成分是水。

 大脑和心脏由 73% 的水组成，

 肺里大约有83%是水。

 皮肤含有64%的水分，

 肌肉和肾脏79%是水，

 甚至骨头都是水的：31% 的水。

 每天，人类必须消耗一定量的水才能生存。

 具体来说，每 1 公斤体重，每 24 小时需要 32.43 毫升水。 在正常的休息状态下。

 当天气变热或变冷时，需要更多的水，并且需要更多的能量活动，例如锻炼、在正常时间以外保持清醒（墓地轮班工作）以及思考问题的解决方案。

 水占您体重的 60% 左右，因此保持充足的水分对您有帮助也就不足为奇了。

 以下是水在您体内工作方式的几个示例：

 调节体温。

 滋润眼睛、鼻子和嘴巴的组织。

 保护身体器官和组织。

 将营养物质和氧气输送到细胞。

 润滑关节。

 水在体内的作用：

 通过身体运输营养物质。

 一旦物质溶解在水中，水对于将其运输到全身至关重要。

 血液 - 83% 是水 - 将氧气、二氧化碳、营养物质、废物等从一个细胞输送到另一个细胞。

 尿液也主要是水。

 由于水是细胞内最丰富的分子，它构成了人类体重的大部分，约占婴儿体重的 75% 和老年人体重的 55%。

 然而，由于人类不断失去水分，因此维持水分平衡至关重要。

 什么是水稳态？

 虽然人体内的水存在于血浆和肠道中，但绝大多数存在于细胞内。 由于人类通过尿液和粪便、汗水和呼吸不断流失水分，因此需要一个精细平衡且敏感的生理控制网络来维持水位。 这是体内水分的稳态，通过口渴刺激液体摄入来维持。

 口渴是一种生物本能，由称为渗透压感受器的感觉受体介导。 这些受体位于下丘脑并检测血浆的变化。 当它们检测到低血量时，它们会向下丘脑发出信号，从而产生口渴的感觉。 这种稳态控制机制确保了液体流失和液体摄入之间的平衡。

 脱水

 脱水一词既指失去身体水分的过程，也指偏离理想的水合状态。 当丢失的液体没有得到补充时，就会发生这种情况，从而阻止身体执行正常功能。

 尽管脱水会影响任何人，但对于腹泻和呕吐后可能会严重脱水的幼儿以及体内水分含量较低的老年人尤其危险。 这意味着即使是轻微的疾病或慢性疾病也会导致老年人脱水。 虽然轻度至中度脱水可以通过摄入液体来逆转，但严重脱水需要药物治疗。

 脱水会导致严重的健康并发症，包括：

 • 热损伤：当因出汗或运动而流失的体液未被补充时，热损伤的范围从轻度热痉挛到热衰竭或危及生命的中暑。

• 癫痫发作：脱水状态也与电解质异常有关。 包括钾和钠在内的电解质有助于细胞之间的电信号传导。 电解质异常会导致细胞间失火，导致肌肉不自主收缩或意识丧失。 患有癫痫等癫痫症的人尤其处于危险之中。 • 泌尿和肾脏问题：严重或反复轻度脱水会导致体内废物和酸的积累，从而使肾脏暴露于过量的肌红蛋白中。 肾脏负责从血液中去除肌红蛋白，但过量可能会导致肾损伤和肾功能衰竭。 • 低血容量性休克：一种危及生命的疾病，由身体血液或体液供应减少 20% 以上引起。 严重的损失会影响心脏向全身泵送足够血液的能力，导致器官损伤和死亡。

 水合作用：意味着每天在醒着的时间内根据个人体重定期饮用适量的白开水。 在一个人的饮食中摄入足够的钠和其他必需矿物质。

 确保充足的液体摄入对于许多功能至关重要。 这些包括：

 • 体温调节：人类被设计来调节体温，特别是在暴露于炎热条件下（如炎热气候或运动期间）。 通过皮肤流失水分（汗水）可以冷却身体并有助于保持体内平衡温度。 然而，如果不补充丢失的液体，体温会迅速升高。

  • 清除身体废物：新陈代谢过程会产生废物，如果保留会伤害身体。 水充当废物的溶剂，将它们溶解并允许它们通过尿液和汗水排出体外。

  • 消化过程：在食物之前、期间和之后摄入的水通过与消化液一起分解食物来帮助有效消化，从而促进通过消化系统的运输。 它还有助于营养物质的吸收。

  尿检。

  尿液中可见水分充足的迹象。

  化学尿胆素负责尿液的黄色色素沉着，并被液体稀释。

  因此，一个人的水分越多，他们的尿液就越清澈。

  深色和强烈气味的尿液是水分不足的明显迹象。