Respiratory regulation of acid-base balance. Renal control of acid-base balance. Acid-base disorders Flashcards
acid-base balance - definition
pH remains in range of 7.36-7.44 for stable internal environment for homeostasis to prevent acidosis/ alkolosis
acids
release H+ into solution
for example - carbonic acid dissociates into h+ and bicarbonate ions
bases
substances that accept h+ and release OH- into solutions
pH
measures concentration of H+ in solution
pH neutral = 7
pH = -log(H+)
buffers - definition
substances that help maintain a stable pH by accepting/ releasing H+ in response to changes in pH
needed to regulate pH in blood
mechanism
bicarbonate buffer system
= primary buffer system in ECF, to maintain pH of blood
when blood pH is too low
- H++HCO3- to form H2CO3 to be converted in CO2 to be exhaled into lungs
when blood pH is too high
-H2CO3⇌H++HCO3− so H+ increases acidity
regulated by lungs/ kidney
peripheral chemoreceptor reflex
located on carotid body + aortic body
detect changes in o2/co2/ph
oxygen too low = more breathing = more oxygen in
central chemoreceptor reflex
located in medulla oblongata of brainstem
detect changes in co2/ ph of csf
too much co2 = more respiration = more co2 out
timing
rapid, within minutes of respiratory disturbance
full compensation takes hours
renal control of acid-base balance - 1
H+ secreted PCT/ DCT/ CD
HCO3- reabsorbed PCT/ loop of henle/ CD
renal control of acid-base balance - 2
kidneys filter out h+ out of blood in PCT/ DCT/ CD
removing excess h+ from the blood, reducing blood acidity
renal control of acid-base balance - 3
NH3 released from kidneys
NH3 + H+ -> NH4+ to reduce acidity
acid-base disorder 1
RESPIRATORY ACIDOSIS
cause
- more co2/ h+
- COPD
- hypoventilation
compensation
- h+ secretion
- hco3- reabsorption
acid-base disorder 2
RESPIRATORY ALKOLOSIS
cause = hyperventilation / anxiety/ pain
compensation
- less h+ secretion
- less hco3- reabsorption
acid-base disorder 3
METABOLIC ACIDOSIS
cause = DKA/ lactic acidosis / diarrhea
compensation
- more ventilation to remove co2