PH BALANCE

Acids are defined as substances which release Hydrogen ions (H+) when  added to water. On the other hand, Bases are those substances which release Hydroxide ions (HO-) on being added to water.  For maintaining homeostasis, the human body ideally should have a blood pH (Potential Hydrogen) value in the range of 7.35-7.45 with normal value of 7.4 (H+), i.e., nearly 40 nmoles/liter, which is slightly alkaline. Values below or above the ranges can prove to be life threatening.

             Blood acidosis may be Metabolic or Respiratory. Metabolic acidosis is caused by intake of substances containing or producing acids, poisoning, alcohol, etc. Other causes could be uncontrolled diabetes mellitus (type 1), malfunctioning kidneys, shock, etc which either result in excess acid or low bicarbonate in the blood. Its symptoms include nausea, fatigue and vomiting. In case of extreme situations, blood pressure may fall with its effects like coma and even death. On the other hand Respiratory acidosis results when lungs do not release sufficient quantity of Carbon-di-oxide due to diseases causing impaired breathing, asthma, chronic bronchitis, pneumonia, etc.. Its symptoms being headache, drowsiness and in bad cases coma. Body tries to combat acidosis by breathing deeply so as to expel excess Carbon-di-oxide and kidneys try to remove  excess acids in urine.

              Alkalosis implies  surplus bicarbonate  or low acid levels in the blood. Similar to acidosis, there are Metabolic and Respiratory alkalosis. Symptoms  include muscle cramps, twitching, etc.  The causes of Metabolic alkalosis could be loss of acids through vomiting , large intake of alkalis,  kidney malfunction, constipation, etc. It can be treated by ingesting water and electrolytes (Sodium and Potassium). Respiratory alkalosis can result from Hyperventilation (deep breathing) caused by fever, pain, anxiety, etc which results in loss of high quantity of Carbon-di-oxide from blood. Lowering the rate of breathing consciously can increase Carbon-di-oxide levels so as to bring the acid-base balance to normal.

             The body’s renal and respiratory buffer maintains the pH balance at a normal level. While the renal buffer is mediated by the kidneys, the respiratory buffer operates through the following chemical equation:

                         H2O + CO2           <->             H2CO3     <->          H+  +  HCO3-
                                                                Carbonic acid              bicarbonate ion

It implies that Carbon-di-oxide combines with water available in the blood to release Carbonic acid which then gives rise to Hydrogen ions and Bi-carbonate ions. The reaction is reversible.

                 Carbon dioxide is a metabolic waste. In situations of enhanced rate of  metabolism, CO2  levels in the blood stream rise, the equation moves to the right  forming more H+ resulting in low pH levels or acidosis. The body counteracts by breathing rapidly and releases excess Carbon-di-oxide raising pH level. Conversely,  low rate of metabolism makes the equation go reverse forming less H+ ions resulting in high pH levels or alkalosis. The body's response is shallow breathing and accumulation of carbon dioxide reducing the pH level.

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