Acid Base Physiology Flashcards
Physiological pH
7.35-7.45
What is the most important issue from high or low pH
Protein structure and function damage
What happens when pH is acutely out of range
Negatively ionotrophic
Air hunger
Cellular disfunction
Affects K+ distribution - maintain electrical neutrality
How does chronic out of range pH affect the body
Effect bones and stone formation
Progress of kidney disease
Where is titratable acid in the body from
Diet
Where is volatile acid in the body from
Cellular respiration
How is acid added to the body
Cellular respiration
Dietary acid
Physiological states at exercise
Pathological states eg ketoacidosis
What pathologies increase acid
Methanol poisoning
Ethylene glycol poisoning
Drugs/toxins
CO poisoning
Hypotension
Hypoxia
Uncontrolled diabetes
Starvation
Which organs excrete acid as part of buffer systems
Lungs
Kidneys
Most important buffer system in body
Bicarbonate
3 minor pH buffer systems
Plasma proteins
Bone
Intracellular phosphates
Is acid excretion quicker in the lungs or kidneys
Lungs
What triggers increased ventilation in response to pH
High pCO2
Low pH
How does the kidneys increase acid secretion from the body
Increase acidity of urine
Where is HCO3 reabsorbed in the kidney
Proximal tubule
Where is H+ excreted from the nephrons to control pH
Distal tubule
Collecting duct
Are acidaemia and alkalaemia conditions or processes
Conditions
Are acidosis and alkalosis conditions or processes
Processes
Compensation
Secondary process trying to oppose the primary one and maintain normal blood pH
Respiratory acid/alkalosis
pH change related to ventilation
Metabolic acid/alkalosis
pH change associated w HCO3 consumption and regeneration
What is the primary abnormality in respiratory acidosis and alkalosis
pCO2
Primary abnormality in metabolic acidosis
Low HCO3
What is used to identify the cause of low HCO3 in metabolic acidosis
Anion gap
What causes metabolic acidosis with a high anion gap
Addition of exogenous acid, no Cl- compensation
Acid ingestion/ poisoning
Lactic / ketoacidosis - acid gen
Renal failure - acid retention
What causes metabolic acidosis with a normal anion gap
Primary loss of HCO3
What can decrease plasma HCO3
Acid ingestion
Acid generation
Acid retention
HCO3 loss
What is a normal anion gap
16
Why is anion gap normal in acidosis caused by HCO3 loss
Compensatory rise in Cl-
What is the commonest cause of normal anion gap acidosis
Diarrhoea
