Water Its Need And Importance Essay Example for Free

Water Its Need And Importance Essay Water is the most abundant substance in the human body ranging from 40 to 80 percent of the body weight. Body water is distributed in two major compartments: the intracellular and the extracellular fluid compartments . Water being a solvent dissolves all substances and acts as a carrier to transport nutrient and other crucial chemicals which are needed for effective functioning of organs. For instance water helps in digestion, by dissolving the nutrient substances and making them pass through gastrointestinal tracks ultimately into the blood stream. It assists in transportation of food through the intestines as well as removing waste products from the body. On a cellular level it acts a medium for transmission of electrical signals between cells. It enables biochemical processes, acts as a lubricant and also regulates the body temperature according to the environmental conditions. FLUID BALANCE: Under normal condition fluid intake equals fluid output and the body maintains constant volume. When the intake exceeds the output, a positive balance or hydration exceeds on the other hand when output exceeds intake a negative balance or dehydration is caused. The major water loss processes are perspiration and urination. The water balance is regulated by osmoreceptors located in the hypothalamus. These receptors sense the molality of the blood and decide whether more or less water is required to correct the osmolality. Thirst is stimulated and we drink water if the blood is too concentrated. Anti-diurectic hormone or ADH is released from the pituitary glands which causes conservation of body fluid by acting on the kidneys leading to decreased urine output. If blood is too dilute then thirst is suppressed and DH is inhibited causing volumes of urine to be excreted. When a person eliminates water through lungs and skin without being aware of it then its called insensible loss. Loss of water in extracellular compartment causes the fluid to become concentrated leading to hypertonicity and a gain in water leads to hypotonicity. In addition to regulating total volume, the osmolarity (the concentration of solute particles per unit volume) of bodily fluids is also tightly regulated. Extreme variation in osmolarity causes cells to shrink or swell, damaging or destroying cellular structure and disrupting normal cellular function. The human body maintains a proper fluid balance through the action of mineral compounds namely from sodium and potassium which are called electrolytes. Electrolytes are chemicals formed by ionic bonding that dissociate into electrically charged ions when they dissolve in the body fluids. Examples are acids, bases and salts. Their primary function is to control osmolarity, maintenance of acid-base balance, metabolism of essential minerals and participation in cellular activities. The sodium pump is a mechanism which ensures that a cell does not retain too much sodium (which attracts water via osmosis across the semi-permeable membrane of the cell wall) and thus stops too much water from entering the cell. As mentioned before ADH plays the key role in lowering osmolarity (reducing sodium concentration) by increasing water reabsorption in the kidneys, enabling to dilute bodily fluids. To prevent osmolarity from decreasing below normal, the kidneys also have a regulated mechanism for reabsorbing sodium in the distal nephron which is controlled by aldosterone, a steroid hormone produced by the adrenal cortex ENVIRONMENTAL FACTORS: Several environmental factors control the loss of body fluids. Higher ambient temperatures result in a greater potential for sweat production. Higher humidity is also responsible for higher sweat production, but effectiveness of sweating to cool the body is reduced due to decreased rate of evaporation of perspiration from the skin. The same problem also exists with clothing that traps sweat against the skin which results in a reduced cooling efficiency that forces a greater sweat rate. CONCLUSION: A regular fluid intake from our daily diet is crucial to maintain good health. This is because the human body does not store water in the way as it stores calories so we need a constant supply every day. About 15 percent of our water needs comes from food metabolism, as our body converts part of our food into hydrogen and then mixes this with oxygen from our lungs to form water. The remaining 85 percent comes directly from water in our diet, either from water-rich foods or from water we drink. For women, the US Food and Nutrition Board recommend a total daily water intake of about 2. 7 liters (about 8 glasses) from all beverages and foods. For men they advise a total daily water intake of about 3. 7 liters (about 12 glasses). REFERENCES: ? http://www. britannica. com/EBchecked/topic/211236/fluid-balance ? http://www. annecollins. com/water-intake-fluid-balance. htm ? http://en. wikipedia. org/wiki/Body_water ? Schaums Outline of Human Anatomy and physiology