PHS 4300 Lecture Notes - Lecture 4: Pseudohypoaldosteronism, Aquaporin 2, Extracellular Fluid

• School: University of Ottawa
• Department: Physiology
• Course: PHS 4300
• Professor: Frank Feiner

Document Summary

General characteristics of acid-base in kidney and lungs ph range of 7. 35-7. 45: ph depends on [hco3-] / pco2, normal ratio of bicarbonate to carbonic acid is 20:1, moles of carbonic acid = pco2 x solubility in water (0. 032) Lungs regulate ph by altering co2 excretion: co2 becomes acid, drop in ph slows breathing to lower pco2. Vice versa: respiratory compensation is immediate. Change in ph may be due to metabolic or respiratory cause. Plasma bicarb is referred to as metabolic component. Cannot sustain ph<7 for long before permanent brain damage. Copd, asthma, emphysema, rib fracture, tumour etc: respiratory alkalosis due to hyperventilation. If renal response does not happen when there is respiratory acidosis/alkalosis, it may indicate abnormal renal function and can be described as underlying renal alkalosis/acidosis. If pco2 does not change in expected direction for compensation of metabolic disturbance, we can conclude there is an underlying respiratory disorder.