What do bicarbonate ions do

Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. Normal bicarbonate levels are:. A high level of bicarbonate in your blood can be from metabolic alkalosis, a condition that causes a pH increase in tissue.

Metabolic alkalosis can happen from a loss of acid from your body, such as through vomiting and dehydration. It may also be related to conditions including anorexia and chronic obstructive pulmonary disease. A low level of bicarbonate in your blood may cause a condition called metabolic acidosis, or too much acid in the body. A wide range of conditions, including diarrhea, kidney disease, and liver failure, can cause metabolic acidosis. The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand.

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Whereas the respiratory system together with breathing centers in the brain controls the blood levels of carbonic acid by controlling the exhalation of CO 2 , the renal system controls the blood levels of bicarbonate.

A decrease of blood bicarbonate can result from the inhibition of carbonic anhydrase by certain diuretics or from excessive bicarbonate loss due to diarrhea. Finally, low bicarbonate blood levels can result from elevated levels of ketones common in unmanaged diabetes mellitus , which bind bicarbonate in the filtrate and prevent its conservation. The steps involved in supplying bicarbonate ions to the system are seen in previous diagram and are summarized below:.

Figure 2. Tubular cells are not permeable to bicarbonate; thus, bicarbonate is conserved rather than reabsorbed. Steps 1 and 2 of bicarbonate conservation are indicated. It is also possible that salts in the filtrate, such as sulfates, phosphates, or ammonia, will capture hydrogen ions. If this occurs, the hydrogen ions will not be available to combine with bicarbonate ions and produce CO 2. In such cases, bicarbonate ions are not conserved from the filtrate to the blood, which will also contribute to a pH imbalance and acidosis.

The hydrogen ions also compete with potassium to exchange with sodium in the renal tubules. If more potassium is present than normal, potassium, rather than the hydrogen ions, will be exchanged, and increased potassium enters the filtrate. When this occurs, fewer hydrogen ions in the filtrate participate in the conversion of bicarbonate into CO 2 and less bicarbonate is conserved. If there is less potassium, more hydrogen ions enter the filtrate to be exchanged with sodium and more bicarbonate is conserved.

Chloride ions are important in neutralizing positive ion charges in the body. If chloride is lost, the body uses bicarbonate ions in place of the lost chloride ions. Thus, lost chloride results in an increased reabsorption of bicarbonate by the renal system. Diabetic acidosis, or ketoacidosis, occurs most frequently in people with poorly controlled diabetes mellitus. When certain tissues in the body cannot get adequate amounts of glucose, they depend on the breakdown of fatty acids for energy.

When acetyl groups break off the fatty acid chains, the acetyl groups then non-enzymatically combine to form ketone bodies, acetoacetic acid, beta-hydroxybutyric acid, and acetone, all of which increase the acidity of the blood.

Ketoacidosis can be severe and, if not detected and treated properly, can lead to diabetic coma, which can be fatal. A common early symptom of ketoacidosis is deep, rapid breathing as the body attempts to drive off CO 2 and compensate for the acidosis. Another common symptom is fruity-smelling breath, due to the exhalation of acetone.

Other symptoms include dry skin and mouth, a flushed face, nausea, vomiting, and stomach pain. Treatment for diabetic coma is ingestion or injection of sugar; its prevention is the proper daily administration of insulin.

A person who is diabetic and uses insulin can initiate ketoacidosis if a dose of insulin is missed. Among people with type 2 diabetes, those of Hispanic and African-American descent are more likely to go into ketoacidosis than those of other ethnic backgrounds, although the reason for this is unknown. A variety of buffering systems exist in the body that helps maintain the pH of the blood and other fluids within a narrow range—between pH 7.

A buffer is a substance that prevents a radical change in fluid pH by absorbing excess hydrogen or hydroxyl ions. Several substances serve as buffers in the body, including cell and plasma proteins, hemoglobin, phosphates, bicarbonate ions, and carbonic acid. The bicarbonate buffer is the primary buffering system of the IF surrounding the cells in tissues throughout the body.

The respiratory and renal systems also play major roles in acid-base homeostasis by removing CO 2 and hydrogen ions, respectively, from the body. Answer the question s below to see how well you understand the topics covered in the previous section. Skip to main content. Search for:. Einstein Sao Paulo. Epub Oct Ital J Pediatr.

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