1. The range of [H+] in nanomoles/L (or pH units) compatible with life is:
    a) 30 - 138 (6.86 - 7.52)
    b) 36 - 168 (6.77 - 7.44)
    c) 16 - 168 (6.77 - 7.80)
    d) 36 - 60 (7.22 - 7.44)
    • c)
    • The range of [H+] compatible with life is approximately 16 - 160 nanomoles/L (pH: 6.77 - 7.80). It should be emphasized that the pH value per se is of limited significance unless seen in the context of the clinical condition of the patient.
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  3. Based on the usual American diet, how does acid (H+) production compare to the extracellular fuid (ECF) H+ content?
    An adult produces roughly 1 mmoles (106 nanomoles) of fixed acid (H+) per Kg of body weight per day. The ECF H+ content is normally about 12 nanomoles. Therefore, the daily acid production is usually a million times larger than the ECF H+ content.
  4. How is the daily acid load (produced in the normal course of metabolism) handled by the body?
    • Fixed acid load is diluted in body fluids which lessens its impact on cell function, then it is buffered by ECF (40%) and ICF buffer bases (60%). A major buffer base is bicarbonate (HCO3-):
    • H+ + HCO3- <---> H2CO3 <---> H2O + CO2
    • The carbon dioxide is quickly eliminated through the lungs, whereas the bicarbonate consumed is eventially replenished by the kidney in the course of net acid execretion. Two thirds of the acid load is ultimately execreted by the kidneys in the form of ammonium which derived from glutamine metabolism.
Card Set
Basic Concepts in Acid-Base Physiology