Maintaining Blood pH

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Maintaining Blood pH
AcidosisAlkalosis
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Maintaining Blood pH
Carbon dioxide is exhaled
Acid entering the blood stream
HCO31- H H2CO3
H2O CO2
Bicarbonate ion circulates in the blood stream
where it is in equilibrium with H and OH-. In
the lungs, bicarbonate ions combine with a
hydrogen ion and lose a water molecule to form
carbon dioxide, which is exhaled.
Kelter, Carr, Scott, Chemistry A World of
Choices 1999, page 291
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Alkalosis
If our breathing becomes too fast
(hyperventilation)
Carbon dioxide is removed from the blood too
quickly. This accelerates the rate of
degradation of carbonic acid into carbon dioxide
and water. The lower level of carbonic acid
encourages the combination of hydrogen ions
and bicarbonate ions to make more carbonic acid.
The final result is a fall in blood H1 levels
that raises blood pH which can result in
over-excitability or death.
Kelter, Carr, Scott, Chemistry A World of
Choices 1999, page 291
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Acidosis
If breathing becomes too slow (hypoventilation)
free up acid, pH of blood drops, with associated
health risks such as depression of the central
nervous system or death.
The normal pH of blood is between 7.2 7.4.
This pH is maintained by the bicarbonate ion and
other buffers.
Kelter, Carr, Scott, Chemistry A World of
Choices 1999, page 291