Acid-base Balance Flashcards
What is an acid
A compund that DONATES and H+ ion
Has a low pH
The more ___ in a solution causes the pH to decrease
H+ ions
What is a base
A compund that BINDS to H+ ions
Has a higher pH
Increasing the levels of a ___ will increase the pH
Base
Why are acid and base levels controlled in the body
To maintain a normal pH range
What is the normal pH range for most domestic species
7.35 and 7.45
pH is determined by the
Level of H+ ions
How are pH ranges maintained
Buffering systems
What happens with a deviation from the normal pH range
Enzyme and cell function will be negatively affected
Can cause death
What is acidosis
When the animal’s pH is lower than the normal range
Increase of acid levels or loss of a base
What is alkalosis
When an animal’s pH is above the normal range
Excess base or loss of acid
What is buffering
The body’s way of balancing acid and base to maintain a constant pH
What are the 3 main categories of buffering systems in the body
Chemical buffering
Ion excretion in the urine
Adjustment of respiratory rate
What are the two metabolic buffering systems in the body
Chemical buffering
Ion excretion in the urine
What is the chemical buffering system
K+ and H+ ion exchange between intracellular and extracellular space
How does the ion excretion in the urine buffering system work
The kidenys control excretion and retention of bicarbonate and H+ to alter pH
How does adjustment of respiratory rate alter pH
By adjusting respiratory rate, carbon dioxide levels in the bloodstream are altered which affects pH
How long does it take for the two metabolic buffering systems to significantly alter pH?
3-5 days
True or false
Respiratory rate can quickly alter pH
True
In a blood gas analysis, whats are the normal ranges of arterial and venous pH
Arterial: 7.40
Venous: 7.35
In a blood gas analysis, whats are the normal ranges of arterial and venous pCO2
Arterial: 40
Venous: 45
In a blood gas analysis, whats are the normal ranges of arterial and venous HCO3
Arterial: 25
Venous: 24
In a blood gas analysis, whats are the normal ranges of arterial and venous base excess (BE)
Both are 0
In a blood gas analysis, whats are the normal ranges of arterial and venous pO2
Arterial: 95
Venous: 40
What is the biggest difference in arterial and venous blood on a blood gas analysis
The levels of oxygen (pO2)
Why is there such a large difference in pO2 levels in arterial and venous blood
Arterial blood has recently been oxygenated (coming from the heart/lungs)
In Venous blood, oxygen has been used up in the tissues so oxygen levels are lower
If the doctor is worried about pulmonary disease in a patient, which sample, venous or arterial, would be most useful in a blood gas analysis
Arterial
How does potassium (K+) work in a buffering system
K+ is in high concentration within cells
When there is a high level of H+ ions (acidosis), they can be exchanged for K+ (H+ shifts into cells and K+ shifts into extracellular space) and increase the pH
What is a risk of the potassium buffering system
Can cause hyperkalemia
What are the symptoms of hyperkalemia
Decreased/irregular heart rate Bradycardia: can slow until death Decreased blood pressure Muscle weakness Lethargy
CO2 + H2O <> H2CO3 <> H+ + HCO3-
What is this equation
The carbonic acid equilibrium equation
In the equation, if H+ increases then CO2____
Increases
True or false
In the equation, H+ has a stronger effect than HCO3- (bicarbonate)
True