Definition
- pH is the negative logarithm of hydrogen ion concentration in a solution; blood pH is normally maintained between 7.35 and 7.45.
Buffer Systems of the Body
- A buffer is a weak acid with its conjugate base salt (or a weak base with its conjugate acid salt) that minimizes pH change when acid or base is added.
The four buffer systems of the body
Buffer
Bicarbonate-carbonic acid
- Site
- Plasma, red cells
- Notes
- Main plasma buffer; works with lungs
Plasma protein (albumin)
- Site
- Plasma
- Notes
- 95% of plasma non-bicarbonate buffer
Phosphate (organic and inorganic)
- Site
- Intracellular fluid, renal tubule
- Notes
- Major intracellular buffer
Hemoglobin
- Site
- Red cells
- Notes
- 85% of red-cell buffering