Acid Base Balance
The degree of acidity or alkalinity of the blood is an important property. The pH scale indicates the acidity or alkalinity of any solution, including blood. The pH scale ranges from 0 (strongly acidic) to 14 (alkaline) (strongly basic alkaline). A pH of 7.0 is considered neutral in the middle of the scale. Blood is naturally slightly essential, with a pH range of 7.35 to 7.45. The pH of blood is usually kept close to 7.40 by the body.
A doctor determines an individual’s acid-base balance by measuring the pH of their blood as well as the levels of carbon dioxide (an acid) and bicarbonate (a base).
Blood acidity rises as the
- The body’s acidic compound level rises (through increased intake or production or decreased elimination)
- The body’s basic (alkaline) compound level decreases (through decreased intake or production or increased elimination)
- Blood alkalinity increases when the body’s acid level falls, or the base level rises.
Acid-Base Balance Control
Acid-base balance refers to the body’s balance of acidity and alkalinity.
The acid-base balance of the blood is precisely controlled because even minor deviations from the normal range can have severe consequences for many organs. The body regulates the acid-base balance of the blood via various mechanisms. These mechanisms entail the
- System of buffers
- The Lungs’ Function
The release of carbon dioxide from the lungs is one mechanism by which the body regulates blood pH. Carbon dioxide, a mildly acidic waste product of the metabolism of oxygen and nutrients (which all cells require), is constantly produced by cells. It then exits the cells and enters the bloodstream. The blood carries carbon dioxide to the lungs, where it is exhaled. The pH of the blood decreases as carbon dioxide accumulates (acidity increases).
The brain controls the rate and depth of breathing to regulate the amount of carbon dioxide exhaled (ventilation). As breathing becomes faster and deeper, the amount of carbon dioxide exhaled increases, as does the pH of the blood. The brain and lungs can regulate blood pH minute by minute by adjusting the speed and depth of breathing.
The Kidneys’ Function
The kidneys can influence blood pH by excreting excess acids and bases. The kidneys can change the amount of acid or base excreted, but because they adjust more slowly than the lungs, this compensation usually takes several days.
System of buffers
Another method for controlling blood pH is to use chemical buffer systems, which protect against sudden changes in acidity and alkalinity. pH buffer systems are made up of the body’s naturally occurring weak acids and bases. Under normal pH conditions, these weak acids and bases exist in pairs that are in balance. By adjusting the proportion of acid and base, pH buffer systems work chemically to minimize changes in the pH of a solution.
Carbonic acid (a weak acid formed from the carbon dioxide dissolved in the blood) and bicarbonate ions are the most critical pH buffers in the blood (the corresponding soft base).
Acid-Base Disorders Classification
There are two types of acid-base imbalance abnormalities:
Acidosis is caused by an excess of acid in the blood, an abnormal loss of bicarbonate from the blood (metabolic acidosis), or a buildup of carbon dioxide in the blood… more info: The blood contains too much acid (or not enough base), resulting in a drop in blood pH.
Alkalosis is a type of alkalosis. Alkalosis is defined as excessive blood alkalinity caused by an excess of bicarbonate in the blood, a loss of acid from the blood (metabolic alkalosis), or a low level of carbon dioxide in the blood… The blood contains too much base (or not enough acid), causing an increase in blood pH.
Acidosis and alkalosis are not diseases but symptoms of various conditions. The presence of acidosis or alkalosis alerts doctors to the presence of a severe problem.
Acidosis and alkalosis types
Acidosis and alkalosis are classified according to their primary cause.
An imbalance causes metabolic acidosis and metabolic alkalosis in the kidneys’ acid or base production and excretion.
Changes in carbon dioxide exhalation caused by lung or breathing disorders cause respiratory acidosis and alkalosis.
People can have multiple acid-base disorders.
Compensation for acid-base imbalances
Each acid-base disturbance activates automatic compensatory mechanisms that return blood pH to normal. In general, metabolic disorders are compensated for by the respiratory system, while respiratory troubles are paid for by metabolic means.
Initially, compensatory mechanisms may restore the pH to near-normal levels. Thus, a significant change in blood pH indicates that the body’s ability to compensate is failing. In such cases, doctors search for and treat the underlying cause of the acid-base disturbance as soon as possible.
Acid Base Balance
Discuss One of the following using the criteria above
(click to access).
1. Discuss what you have learned related to the
body’s response to heat (#1_Take away
2. Describe what you believe your response
should be as a lay person to give assistance
(#2 _Lay person’s assistance)
3. The body can only handle a certain amount of
heat, and if that degree is extended, the body
may end up closing down. Explain why this is
so (#3 Body’s response to heat)
4. Respond to the diagram below titled Heat
Dangers. Provide one quote from the textbook
or Web to support your thinking (#4_ Heat