I. Acid-Base Balance

     A.   Blood pH
          1.   remains in rigid constraints
               a.   7.0 - 7.8
               b.   arterial = 7.40 at rest
               c.   venous = 7.36 at rest
                    (1)  the difference is due to CO2 production
                         (a)  CO2 + H2O <=> H2CO3 <=> H+ + HCO3-

     B.   Muscle pH
          1.   less than the pH of blood
               a.   about 7.0
               b.   because the metabolic processes are constantly
                    producing CO2
          2.   w/exercise, LA further lowers the pH   (6.4 max)

     C.   Intercellular fluid
          1.   is equal to the pH of the venous blood

     D.   Sweat (acid)
          1.   5.9 - 6.1 
               a.   may fluxuate outside range, depends on the
                    body chemistry
     E.   Urine
          1.   (4.7 - 8.0) large range
               a.   kidneys regulate depending on how the body
                    chem is
     F.   Saliva
          1.   (5.7 - 7.0)
          2.   made of digestive juices
          3.   varies depending on which gland is secreting fluid

     G.   Stomach   (1 - 6)   very acidic
          1.   prod. HCL-     very strong
          2.   will make a broad flux, depending on the amount of
               HCL-
          3.   stress may produce the increase in HCL-

     H.   Pancreas  (pancreatic juices)  7.6 - 8.0   alkaline
          1.   foods leace the stomach as acid
          2.   in the duadenum, the pancreas adds this juice

     ***  NEED TO KNOW:

          *    URINE VARIES CONSEDERABLY, DEPENDING ON WHAT
               PRODUCT IS BEING EXCRETED.
          *    STOMACH IS ACID
          *    KNOW THE NUMBERS FOR THE pH RANGE OF BLOOD, FROM
               NORMAL TO EXTREME

I.   Acid fluids / body fluids
          
     A.   Major threat to pH body fluids
          1.   formed in metabolic process
               a.   found in 3 groups
                    (1)  Volitile
                    (2)  Fixed Acid
                    (3)  Organic

     B.   Volitile    (consists of CO2)
          1.   called volitile as it gives off CO2
          2.   can blow off the CO2 by breathing heavily
          3.   w/ exercise, we increase production of CO2 because
               we increase the metabolic rate
               a.   but we also breath more also

     C.   Fixed Acid     (made primarily of sulphuric and
                         phosphoric acid)
          1.   sulphuric acid = process of A.A.'s that contains
               sulpher
          2.   Phosphoric acid comes from phospholipids and
               neuclaic acid
          3.   These are not the results of exercise, but rather
               diet

     D.   Organic acids  (acetoacetic acid and LA)
          1.   acetoacetic acid
               a.   first stage in the Kreb Cycle  (after Acetyl
                    CoA)
               b.   comes from partial breakdown of fats
                    (1)  leads to ketosis
          2.   Lactic Acid   (fairly strong acid)
               a.   this is formed in muscle cells, then diffuses
                    to rest of the body and causes problems
               b.   WHY ??
                    (1)  The H+ ions of the LA combine W/ other
                         molecules and change their shape, size,
                         and function, thus changing the persons
                         metabolism
                    (2)  H+ ions decrease the ability to form ATP
                         by anaerobic and aerobic processes by
                         inhibiting the ability of the enzymes.
                    (3)  They also compete with Ca++ for binding
                         sites on the troponin

II.  Control systems to conrol pH

     A.   Buffers
          1.   found in the body fluids everywhere
               a.   in cells, blood, between cells, etc
          2.   lots and lots of buffers
          3.   **  Act very quickly   (fractions of a second)
          4.   combines with H+ ions
          5.   removes them from solution
          6.   holds them in solution until the situation is in
               control, then releases them into solution
          7.   What influences the effiency of the buffers
               a.   effiency of buffers to combine w/ H+ ions
               b.   amount of buffers present

     B.   Respiratory System
          1.   Manipulates the amount of CO2 present
               a.   if you double the breathing volume, this will
                    raise the pH by .25
               b.   decrease the breathing rate, decrease the pH
                    by .25
          2.   Resp. center in the medulla is very sensitive to
               changes.
          3.   These changes cause an ncrease in the resp.
               a.   happens in a matter of minutes

     C.   Kidneys
          1.   Imp. reg. of acid / base balance.
          2.   Takes 8 - 24 hours before they really start
               regulating the H+
          3.   Can secrete acid or base depending on what there is
               too much of
          4.   Examples:
               a.   secretes ammonia (NH3) which turns to ammonium
                    (NH4+)
               b.   secrete more bicarbonate ions to combine with
                    the H+ ions
               c.   if too alkoline, it gets rid of the
                    bicarbonate ions