Acid-base balance and imbalance Flashcards
Formula for pH
- log [H+]
Acids are
Hydrogen donors
Bases are
Hydrogen acceptors. This could be by releasing OH- which then combine with H+ to give water
Strength of an acid
It’s tendency to dissociate, producing hydrogen ions in solution
Strong acids
Dissociate completely in soln
Weak acids
Dissociate partially in soln
E.g of weak acids
Lactic and Carbonic
E.g of strong acids
HCl and Sulphoric
Dissociation constant (K)
Property by which acid strength is measured
Formula for K given a reaction: HA ↔ H+ + A-
[ H+ ] [ A- ]
Ka = [ HA ]
pH of blood
7.35-7.45
pH of ECF
7.4
pH during acidosis
below 7.35
pH during alkalosis
above 7.4
pH range for survival
6.8 - 8.0
3 reasons for maintaining pH balance
Most enzymes function only within a certain pH range
Electrolytes are affected by the pH
pH affects hormones
which is produced more in the body: acids or bases
acids
4 processes that produce acids in the body
They are gotten from food
By metab of proteins, lipids and nucleic acids (produces phosphoric and sulphuric acids)
Incomplete metab of fats and carbs produce acids such as lactic acid
Complete metab (aerobic) produces co2 which could still affect pH levels
co2 forms which acid in soln
carbonic
two systems for controlling acids and bases
Chemical buffers
Physiological buffers
E.g of chemical buffer system
Protein, Hemoglobin, bicarbonate and phosphate
What is a buffer
A buffer a soln that resists drastic pH change. It is composed of a weak acid and it’s conjugate base.
E.g of physiological buffer system
Renal system
Respiratory system
volatile acids
ones that can be excreted as gas through the lungs
fixed acid
ones that can’t be breathed off
Hypercapnia
High co2 levels in the blood
hypercapnia causes
Chronic:
Depression of brain respiratory center could be caused by head trauma or drugs
Paralysis of the chest muscles/respiratory muscles
Emphysema
Acute:
Adult Respiratory Distress Syndrome
Pulmonary edema
Pneumothorax or pneumonia
Compensation for respiratory acidosis
More H+ is excreted and more HCO3 - is generated by the kidneys, increasing blood HCO3 -
Symptoms of respiratory acidosis
Shortness of breath
Restlessness
Lethargy
Coma
Disorientation
Skin warm and flushed due to vasodilation of blood vessels by excess co2
Respiratory acidosis treatment
Restore ventilation
IV lactate solution
Treat underlying dysfunction or disease
