The Water needs, the power of water

Album photos Collection N#3267


1- The Water in You.
2- The Water and the Human Body.

On Earth:

One factor in estimating when water appeared on Earth is that water is continually being lost to space. H2O molecules in the atmosphere are broken up by photolysis, and the resulting free hydrogen atoms can sometimes escape Earth's gravitational pull. When the Earth was younger and less massive, water would have been lost to space more easily.

The Water needs, the power
of water - Photo N#1

Any water on Earth during the latter part of its accretion would have been disrupted by the Moon-forming impact (~4.5 billion years ago), which likely vaporized much of Earth's crust and upper mantle and created a rock-vapor atmosphere around the young planet. The rock vapor would have condensed within two thousand years, leaving behind hot volatiles which probably resulted in a majority carbon dioxide atmosphere with hydrogen and water vapor. 

Afterward, liquid water oceans may have existed despite the surface temperature of 230 °C (446 °F) due to the increased atmospheric pressure of the CO2 atmosphere. As the cooling continued, most CO2 was removed from the atmosphere by subduction and dissolution in ocean water, but levels oscillated wildly as new surface and mantle cycles appeared.

The Water needs, the power
of water - Photo N#2

Taste and odor

Pure water is usually described as tasteless and odorless, although humans have specific sensors that can feel the presence of water in their mouths, and frogs are known to be able to smell it. However, water from ordinary sources (including mineral water) usually has many dissolved substances, that may give it varying tastes and odors. Humans and other animals have developed senses that enable them to evaluate the potability of water in order to avoid water that is too salty or putrid.

We can live quite a long time without food, until we have used all our reserves, but we can survive only a couple of days without water. This is because water is the largest component in our body, from 75% body weight for a baby to 50% for elderly people and we cannot make any reserves. As we lose around 2.6 liters daily (sedentary person of normal weight) we must replenish it daily too.

The Water needs, the power
of water - Photo N#3

Phases of ice and water.

The Water needs, the power
of water - Photo N#4

What is the role of water in our body?

Two thirds of our water is found in tissue cells and one third is extracellular, that is in organs, blood, lymph and other fluids.

In the cells, water makes chemical reactions possible by dissolving and transporting minerals and other nutrients.

In the blood, lymph and urine, water helps transport nutrients, cells, hormones, and products of metabolism.

The Water needs, the power
of water - Photo N#5

In organs, water allows secretions, such as hormones, enzymes and salts used for digestion as well as the products of digestion. Water is also an important element of eyes and tears.

In muscle and joints, water plays a role in structure and mechanical function.

Finally, in skin, water participates in body temperature regulation through evaporation by perspiration/transpiration.

The Water needs, the power
of water - Photo N#6

How is the water balance regulated?

As water cannot be stored in our body, it must remain at a constant level; water intake must equal water losses.

We lose water through the skin (350 ml) on top of normal perspiration (150 ml), through respiration (450 ml), through the intestines (150 ml) and in urines (1500 ml). Some of those losses can vary; for example perspiration increases if we are in a warm environment, if we practice sport, if we have a fever or under a strong emotion.

Losses in urine and water intake are the main ways by which water balance is regulated in our body.

The Water needs, the power
of water - Photo N#7

Water serves a number of essential functions to keep us all going:

• A vital nutrient to the life of every cell, acts first as a building material.
• It regulates our internal body temperature by sweating and respiration.
• The carbohydrates and proteins that our bodies use as food are metabolized and transported by water in the bloodstream.
• It assists in flushing waste mainly through urination.
• acts as a shock absorber for brain, spinal cord, and fetus.
• forms saliva.
• lubricates joints.