Blood buffer

Carbonic Acid-Bicarbonate Buffer System

CO2 + H20 equi h2co3 equi H+ + HCO3-

When acid goes up too much, it shifts the equation to the left, meaning there is more Co2 to be exhaled.

Causes of Acidosis

• Hypoventilation
• Diarrhoea
• Diabetes

Causes of Alkalosis

• Hyperventilation
• Vomiting

Shortcomings

Can’t prevent against changes in pH from elevated or depressed levels of CO2. So if the breathing is screwed, the kidneys can compensate to an extent, but its not the same. Thus, long term problems in respiratory rate or efficiency, like those caused by COPD, can lead to problems in haemostasis.

Combating acidosis

If there are no bicarbonate ions left, its bound to phosphate and excreted in urine. This means that when a bicarb is released by the equation the bicarb has an alkali effect on the system, helping to reverse the effect of the acidosis even more.

Diabetic ketoacidosis

Affects type 1 diabetes. When there is a lack of insulin, the liver panics. It thinks "I'm starving", and starts to break down body. This releases energy, but also releases ketones. These ketones are highly acidic, and will start to lower blood pH, which is what causes the crisis. See the page on ketoacidosis for more.