Dr. Richa Singh,
Assistant Professor, Home Science,
G.V.P.G. College Risia (Bahraich)
Water is by for the most important inorganic component of the organism. Water is the largest constituents of the body, about 55 to 60 percent of the total body weight consisting of water [1]. The water content of soft tissues ranges from 70 to 80 percent, while that of bone and adipose tissues (fat) contain relatively lower water contant i.e. about 20 percent. Thus proportion of water in a tissue or in the whole body depends on the proportion of fat in it.
Water is more important than food and deprivation of water brings about death much more rapidly than deprivation of food. Loss of about 10% of the body water causes illness and a further loss of about 15 liter of water may cause death in a few days.[2].
Water is a structural component and cushion of all cells and provides the media in which the chemical reactions of the body takes place and subtance are transported. Water is tightly bound in bone, but in most tissues a content interchange between intracellular and extracellular fluid is occuring in order to maintain osmatic pressure relationships. It has a high specific heat for which, it can absord or gives a heat without any appriciable change in tempreture. Water has a very high latent heat. Thus, it provides a machanism for the regulation of heat loss by sensible or insensible perspiration on the skin surface. Water is the medium of all body fluids, including the digestive juices, the lymph blood, the wine and the perspiration.
Water is the solvents for the products of digestion holding them in the solution and permitting them to pass through absorbing walls of the intestinal tract into the blood stream. The fluidity of blood is because of water.
Water regulates the body tempreture by taking up the heat produced in cellular reactions and distributing it throughout the body. Water is essential as a body lubricant; the solvia the make possible the swallowing of food the mucous secretions of the gastrointestinal and respiratory tracts; the fluids that bathe the joints etc. Protien also produces water which is named Metabolic water.[3]
As nutrients and cellular wastes are soluble in water , nutrients are carried to the cells and wastes are removed to the lungs. A person 75 kg body has 52 kg water in average. [4]
ELECTROLYTE BALANCE
An Electrolyte is any substance that dissociates into it’s components ions when dissolved in water. It is so named because an electrical current can be transmitted by a solution containing any one of these substances Cations carry positive electrical charge while Anions carry negative charge. The electrolyte balance of the body is studied by determining the electrolyte concentration in blood plasma and other body fluids. Tissue cells and red blood cells contain large amounts of potassium phosphates, bicarbonates and small amounts of sodium and chloride ions. The concerteation of K is about 110m Eq/liter while that of sodium is about 20m Eq.
Extracelluar fluid includes plasma, lymph and intrastitial fluids. They contains large amounts of NaCl and bicarbonate ions. Concentration of Na in the above fluid is about 143 m Eq/liter while that of potassium is 5 m Eq. Cell membranes are permeable to water and to nutrients, like glucose, lactose acetoaceatate, aminoacids and inorganic phosphate ions. The body has saveral machanisms by which it can keep the electrolyte balance in the introcellular and extracellular fluids at a constent level. Even though intracellular fluids contains large quantities of K ions and extracellular fluid (ECF) contains large quantities of Na ions. The Movement of Na ions in to ICF or K ions in to ECF is controlled by active transport machanism. This active transport machanism prevents the passage of Na ion into ECF by the continious expenditure of chemical energy.
Potassium ion can be taken by tissue cells or red cells even when the intracellular concentration of K ion for exceeds the extracellular concentration (ECF). The cells can maintain at equilbrium a higher concentrations of K ion inside it’s membrane boundary than the concentration in the ECF. Prevention of movement of K ions from cells to ECF and Na ions from ECF into cells. Movement of Na K and Ca ions in nerve.
Kidneys Play important role in the maintaince of electrolytes balance. Salts are either excreted or conserved by the Kidney depending on the dietary intake and physiological needs.
Variation in Electrolyte concentration and ECF Volume:-
Wide variations in electrolyte concentration and ECF volume can occur in many conditions. They may be broadly grouped into two heads;
(i) Expansion in ECF volume:-
(a) Hypertonic Expansions:- This can occur as a result of drinking hypertonic salt solutions. The ECF becomes hypertonic & hence water is drawn out from the tissue cells causing dehydration of tissues. Serum Sodium levels are high.
(b) Hypotonic Expansions:- This can arise out of drinking large amounts of plain water or infecting large volumes of normal glucose solution without NaCl. The ECF is hypotonic & water is drawn into the tissue cells. Serum sodium levels are low.
(c) Istonic Expansion:- This can occur due to administration of excessive amounts of normal saline. ECF volume is increased. Water is retained in the body. Oedema of the lungs and extermities occur. Serum Sodium levels are normal.
(ii) Decrease or Contaction in ECF volume:-
(a) Hypertonic Contraction:- Deminished water intake can cause dehydration. The Deminished intake may be due to non- availability of water due to loss of salt free fluid in sweating in hot climates or loss of excessive amounts of water in urine. The ECF is hypertonic and draws water from the ICF. A state of dehydration of tossue occures Serum Sodium levels are high.
(b) Hypotonic Contraction:- More salt than water is lost from the body. This can occur in NaCl deficieney when large quantity of water is drunk by persons working in hot climates.
(c) Isotonic Contraction:- This occurs in conditions like sevear diarrhaea or vomitting haemorrhage where isotonic fluids are lost from the body. Decrease in ECF volume leads to fall in blood pressure, circulatory failure and renal failure. Blood urea & NPN are increased.
Balance of some Important Electrolytes:-
(a) Sodium it is found principally in ECF. it helps to maintain the fluid and acid base balance of the body. Any disturbance in the concentration of sodium in extacellular fluid has a serious effect on oesmetic pressure and on acid balance. Daily need of Sodium is 5 to 10 gram per day [3]
Sodium in the diet is almost completely aboorbed from the gastro intertinal tract. Any excess is repidly excreted in the urine.[2]. A person who is perspiring heavely well also loose much sodium that is excreated is regulated by adrenal harmones so that the excretion of the kindey is increased. But if the body stores of sodium or the dietary supply are low only traces of sodium will be excreated by the kidneys.
When the kidneys or heart is not functioning normally, sodium may accumulate in the tisssues & water level also be held. However, excessive pressure, severe vomiting or dieairhoea or disease of the adrenal gland may lead to depletion of body sodium.
(b) Potassium. It is the principle element within the cells. Potassium is essential for the synthesis of proteins & for enzymes function within cells and for the small amount of potassium is also found in extracellular fluid and acids in the regulation of muscle contraction. It regulates our heart
beating [3]
Any condition that reduces the avaiability of nutrients for absorption can lead to potassium depletion for eg prolonged vomiting, gastic, drainge etc. Potassium deficieney may also occur due to defective food intake such as severe malnutrition, chronic alcohalism. However, potassium excess occure in renal failure, severe dehydration and adrenal insufficiency. It result in cardiac failure with the heart stopping in systole. It can be corrected by using a low potassium, low protin, liberal carbohydrate diet.
Since 1970, in India ‘Gramin Jal Aapurti Karyakram’ has been started with the help of UNICEF to provide safe water for the community [2]. UNICEF also developed a high quality hand pump which is exported about 40 contries in the world. Life is not possible without water, as it is a source of some important minerals like sodium and potassium .
Reference:
(1) Bisaria, P. Yadav V.S, Kushwaha Y.S. (2022), Bhajan Poshan and Hygine, Prabhat Prakashan, 4/19 Asaf Ali Road, New Delhi.
(2) Sinha, K. (2022), Food, Nutrition and Hygine, Rakhi Prakashan Pvt. Ltd. Sanjai Palace Agra.
(3) Bakshi, B.K. (2020), Fundamentals of food and Nutrition, Sri Vinod Rustak Mandir, Agra-2.
(4) Pandey, Kanti (2018), Abhinav Gridha Vigyan, Gyanda Prakashan, Ansari Road, Dariya Ganj, New Delhi.
