The document discusses three major mechanisms that regulate acid-base balance and pH in the body: 1) Acid-base buffer systems including the bicarbonate-carbonic acid buffer system and phosphate buffer system that help maintain pH levels, 2) The respiratory system which removes carbon dioxide through hyperventilation to regulate pH, and 3) The renal system which excretes excess hydrogen ions or retains bicarbonate ions in the blood to balance pH levels. These three mechanisms work together to keep blood pH levels within a narrow range around 7.4.

1. ACID-BASE BALANCE..

4. Acid–base homeostasis…
• The Proper Balance Between Acids
And Bases.
• In Other Words, The PH.
• The body has three major
Mechanism To Regulate The
Physiological Acid Base Balance Or
PH Balance As Follows..

5. Three major Mechanism…
1.Acid-base buffer systems.
a)Bicarbonate-carbonic acid buffer
system.
b)Phosphate buffer system.
c)Protein buffer system.
2.Respiratory mechanism.
3.Renal mechanism

6. 1.Acid-base buffer systems.
a)Bicarbonate-
carbonic acid buffer
system.
• The main job of the
carbonic acid/bicarbonate
system is to regulate body
pH.

7. .The PH the blood is
dependent only on the
ratio of the amount of
CO2 present in the blood
to the amount of HCO3
-
(bicarbonate ion) present

8. THE NORMAL
BLOOD PH IS
7.4

9. This ratio remains relatively
constant, because the
concentrations of both buffer
components (HCO3
-
and CO2)
are very large, compared to
the amount of H+
added to the
blood during normal activities
and moderate exercise.

10. If acid is added, the PH
decreases and the
buffer shifts toward
greater H2CO3 and CO2
concentration. (less
than 7.4)

11. As base is added, the PH
increases and the buffer
shifts toward greater
HCO3
-
concentration
(above 7.4)

12. b) The phosphate buffer system
consists of two ions:
• 1.Dihydrogen Phosphate Ions .
• 2.Hydrogen Phosphate Ions.
• When The Number Of Hydrogen Ions In A
Body's Bloodstream Increases (PH Drops),
Hydrogen Phosphate Ions Accept
Hydrogen Ions In Order To Maintain The
Equilibrium Between The Concentration
Of Hydrogen And Hydroxide Ions Within
The Bloodstream.

13. When The Number Of Hydrogen
Ions In The Bloodstream Decreases
(PH Increases), The Resulting
Dihydrogen Phosphate Ions
Release Hydrogen Ions In Order To
Increase The Number Of Hydrogen
Ions In The Blood.

14. C.PROTEIN BUFFER SYSTEM
• Hemoglobin (Hb) is an excellent
buffer because of it's ability to bind
with Hydrogen ions forming a weak
acid and carbon dioxide (CO2). After
oxygen is released in the peripheral
tissues, hemoglobin binds with CO2
and H+ ions.

15. As the blood reaches
the lungs these actions
reverse themselves.
Hemoglobin binds with
oxygen, releasing the
CO2 .

16. 2 RESPIRATORY MECHANISM….
• The most rapid
mechanism that
responds is the
respiratory system by
hyperventilation.
• This removes
quantities of CO2
thereby maintain pH.

17. The hyperventilation
controlled by the
"Respiratory Center"
which is located largely in
the medulla oblongata of
the brain stem..

18. 3.Renal mechanism of acid base
balance…

19. • If acid is excreted in the
urine, its is in effect
removed from the blood
when an equal quantity
of bicarbonate is added
to the blood.
• If the blood is too acidic
more hydrogen ions are
excreted, if the blood is
too basic, then less
hydrogen ions are
excreted.
HCO3
-
+ H+ <===> H2CO3<===>
CO2+H2O

20. Formation of ammonia……
• Ammonia is obtained from urea
cycle which is reacts with
hydrogen ion and forms
ammonium ion which is excreted
through urine.
• Na+-H+ exchanger, the Na+-K+-2Cl-
transporter and on Na+-K+-ATPase

21. All buffer systems are depends each other…..