The document discusses electrolyte and acid-base balance. It defines electrolytes as substances that release ions in water and lists their main functions. The most important electrolytes are sodium, potassium, chloride, calcium, and phosphate. It then discusses each electrolyte in more detail. The document also covers acid-base balance, noting the normal pH range and what constitutes acidosis and alkalosis. It explains how buffers help resist pH changes and lists examples. Finally, it summarizes respiratory and renal regulation of pH through processes like bicarbonate reabsorption and ammonium ion excretion.

1. BinYameen Roll no :0122-011
Khaleel Ahmed Roll no ; 0122-019
Assigned By ; Sir, Jawaad Ahmed
Azizullah R0ll no ;- 0122-010
Topic ;- Electrolyte & Acid-Base Balance

2. Electrolytes balance
Electrolytes are chemical substances that release
cations (positive charge ions ) and anions (negative
charge ions) when dissolve in the water.
Functions of electrolytes
As essential minerals (e.g. iodine, calcium)
Control osmosis between body compartments by
establishing proper osmotic pressure(e.g. sodium,
chloride)

3. Help maintain acid-base balance (e.g. hydrogen
ion, bicarbonate ions)
Carry electrical current that allows the production
of action potential (e.g. sodium, potassium).
Most important electrolytes includes Na+, K+, Cl-2,
Ca++, and HPO4-2.

4. Sodium Ion(Na+)
It is the most abundant ECF cation , involved in
nerve impulse transmission, muscle contraction, and
creation of osmotic pressure.
Cloride Ion (Cl-)
It is the major ECF anion; involved in regulating
osmotic pressure between body compartment, forming
HCl in stomach , and involved in the “ cloride shift”
process in blood,

5. Potassium( K+
It is the most abundant cation, in ICF ; involved
in maintaining fluid volume, nerve impulse
transmission, muscle contraction, and regulating PH.
Calsium ( Ca++
It is the most abundant ion in our body,located
mainly in ECF, major structural component of

6. bones and teeth; functions in the blood clotting,
neurotransmission release , muscle tone, and
excitability of nervous and muscle tissue .
HPO4-2
It is an important ICF anion; another major
structural component of bones and teeth; required for
synthesis of nucleic acids and ATP, and for buffering
reactions.

7. Levels of electrolytes are mainly regulated by
hormones
Aldosterone (from adrenal cortex)
It causes an increase in sodium
re-absorption and potassium secretion at the kidney
tubules .
Parathyroid hormone (PTH)
From the parathyroid gland

8.  Calcitonin (CT)
Frome the thyroid gland regulate calcium
balance.
Regulation of electrolyte intake & output
Electrolyte intake :
•Electrolytes are usually obtained in sufficient
quantities in response to hunger and

9. thirst mechanism.
•In a sever electrolyte deficiency , a person may
experience a salt craving.
Electrolyteoutput:
•Electrolytes are lost through perspiration , feces
and urine . The greatest electrolyte loss occurs as a
result of kidney functions .
•Quantities lost vary with temp; and exercise .

10. ACID-BASE BALANCE
Normal pH
The pH of plasma is 7.4 (average hydrogen ion
concentration of 40 mol / L ) . In normal life, the variation of
plasma pH is very small . The pH of plasma is maintained
within a narrow range of 7.38 to 7.42.
The pH of the interstitial fluid is generally 0.5 units below that
plasma.
Acidosis
If the pH is below 7.38, it is called acidosis. Life is
Threatened when the pH is lowered below 7.25 . Acidosis
leads to CNS depression and coma . Death occurs when pH
is below 7.0.
Alkalosis
When the pH is more than 7.42, it is alkalosis. It is very
Dangerous if pH Is increased above 7.55. Alkalosis induces
neuromuscular hyper-excitability and tetany.

11. BUFFERS
Definition
Buffers are solutions which can resist changes in pH
when acid or alkali is added.
Composition of a Buffer;-
Buffers are of two types:
a. Mixtures of weak acids with their salt with a strong base or
b. Mixtures of weak bases with their salt with a strong acid.
A few examples are given below:
i. H2CO3 (Bicarbonate buffer)
NaHCO3 (carbonic acid and sodium bicarbonate)
ii. CH3COOH/CH3COO Na (Acetate buffer)
(acetic acid and sodium acetate)
iii. Na2HPO4/NaH2PO4 (Phosphate buffer

12. How do Buffers Act?
i. Buffer solutions consist of mixtures of a weak acid or
base and its salt.
ii. To take an example, when hydrochloric acid is
added to the acetate buffer, the salt reacts with the
acid forming the weak acid, acetic acid and its salt.
Similarly when a base is added, the acid reacts with
it forming salt and water. Thus changes in the pH are
minimized.
CH3–COOH + NaOH → CH3–COONa + H2O
CH3–COONa + HCl → CH3–COOH + NaCl
iii. The buffer capacity is determined by the absolute
concentration of the salt and acid. But the pH of
the buffer is dependent on the relative proportion of
the salt and acid.

13. iv. When the ratio between salt and acid is 10:1 , the pH will
be 1 unit higher than the pKa. When the ratio between
salt and acid is 1:10, the pH will be 1 unit lower than the
pKa.
.

14. Respiratory Regulation Of pH
The second line of defense
 It functions by regulating the concentration of
carbonic acid (H2CO3) in blood by lungs.
 The respiratory centers in pons and medulla
regulates the removal or retention of CO2 and
thereby H2CO3 from extracellular fluid by the
lungs.

15. When there is fall in pH of plasma , the respiratory
rate is stimulated resulting in hyperventilation. This
would eliminate more CO2 thus lowering the H2CO3
level.
Increase in OH depresses respiratory ventilation
and release of CO2 from blood.
The increased blood CO2 will result in the
formation of more H2CO3 acid to neutralize excess
alkali .

16. Action Of Hemoglobin
The hemoglobin serves to transport the CO2
formed in the tissue.
It serves to generate bicarbonate or alkali
reserve by the activity of carbonic anhydrase,
CO2+H2OH2CO3
H2CO3HCO3+H+
H+
+Hb HHb

17. Removal of CO2 from Muscle

18. The reverse occur in lungs during oxygenation and
elimination of CO2.When blood reaches the lungs , the
bicarbonate re-enters erythrocytes by reversal of
chloride shift . It combines with H
+
liberated on
oxygenation of hemoglobin to form carbonic acid
which dissociates into CO2 and H2O.CO2 is thus
eliminated by the lungs.
HHb + O2HbO2 +H+
HCO3 +H+H2CO3

19. Removal of CO2 by lungs

20. Renal Regulation Of pH
An important function of kidney is t regulate the pH
of extracellular fluid. Normal urine has a ph around
6,thid pH is lower than that of extra cellular fluid .
This is called acidification of urine. The ph of urine
may vary from as low as 4.5 to as high as 9.8,
depending on the amount of acid excreted.

21. Excretion of H+
Occurs in proximal tubule.
It dissociates to form HCO3- and H+.
H+ is secreted in exchange for Na+.
Net production of HCO3- and net excretion of H+.
Mechanism serves to increase the alkali reserve.

22. Excretion of H+

23. Re-absorption Of
Bicarbonate
This mechanism is responsible to conserve HCO3-.
Normal urine is almost free from HCO3-.
No net excretion of H+.
HCO3- freely diffuse from plasma into tubular
lumen.
HCO3- combines H+ secreted by tubular cells

24. To form H2CO3- and cleavages to CO2 and H2O.
These transport in tubular cells and combines to
form H2CO3-.
H2CO3- dissociates into H+ and HCO3-.
HCO3- is reabsorbed into plasma in association
with Na+.
Helps to maintain steady state.

25. Re-absorption of bicarbonate

26. Excretion Of Ammonium Ions
Help to excrete H+ and reabsorb HCO3-.
Tubular cells deamidate glutamine to glutamate
and NH3 by glutaminase .
NH3 diffuses into tubular lumen and combines
with H+ to form ammonium Ion NH4.
NH4 is therefore, excreted into urine.

27. Excretion of ammoniumions