Flashcards in 13. Acid-Base Homeostasis Deck (16):
what is the purpose of buffering systems?
to maintain normal pH in the body
what buffering systems can be found in the body?
6. Misc. organic acids
what does the homeostasis of H+ ions require?
a balance between H+ production and regeneration of HCO3-
what are the sites of acid-base metabolism?
which organs are the main sources of excretion of acid?
lungs and kidneys
breathing is controlled through hydrogen ion concentration
what causes a right shift in the the oxygen-haemoglobin dissociation curve?
increased 2,3 diPG
Acidosis, increase of H+ ions
what are the problems that could arise with regards to acid-base pathology?
what compensatory mechanisms exist to counteract acid-base pathology?
2. renal bicarbonate regeneration (takes about 1-2 days)
3. hepatic shift between urea synthesis and ammonia excretion
urea cycle change (takes about a week)
what are the causes of metabolic acidosis?
1. increased H+ formation
2. acid ingestion
3. reduced renal H+ excretion
4. loss of bicarbonate
what are the causes of metabolic alkalosis?
1. generation of bicarbonate by gastric mucosa
2. renal regeneration of HCO3- in hypokalaemia
administration of bicarbonate
what are the consequences of metabolic alkalosis?
K+ enters cells and uric
PO4 enters cells
How does respiratory acidosis result?
CO2 retention due to
1. inadequate ventilation
2. parenchymal lung disease
3. inadequate perfusion
how does respiratory alkalosis result?
increased CO2 excretion due to excessive ventilation producing alkalosis
what stimulates increased H+ formation?
diabetic or alcoholic ketoacidosis
inherited organic acidosis
how does diabetic ketoacidosis result?
pre-renal uraemia due to osmotic diuresis