Acid-base balance — Flashcards

Flashcard 71: In the lumen of the late distal tubule and collecting duct, secreted H+ combines with HPO4^2- to form H2PO4^-, which is a(n) _____ acid

Answer: titratable

Extra: Phosphate is the most important titratable acid buffer because its pKa (6.8) is close to the tubular fluid pH. (Note: Titratable acidity specifically excludes NH3/NH4+).

Flashcard 72: In the lumen of the collecting duct, _____ and _____ combine to form NH4+

Answer: NH3

Extra: This process is known as **diffusion trapping**.\n\nIn the **proximal tubule**, NH4+ is secreted directly into the lumen (substituting for H+ on the Na+/H+ exchanger).

Flashcard 73: Pepsinogen is secreted in response to _____ and local H+

Answer: vagal stimulation

Flashcard 74: HCO3- is transported from the cells of proximal tubule into the blood by _____ cotransport and Cl--HCO3- exchange

Answer: Na+-HCO3-

Extra: Watch associated Bootcamp video

Flashcard 75: Neurological disorders (e.g. ALS, Guillain-Barré, polio, MG, botulism) may cause _____

Answer: respiratory acidosis

Flashcard 76: Besides a type II RTA, what acid-base disorder may be caused by acetazolamide? _____

Answer: Normal anion gap metabolic acidosis

Extra: Sketchy Pharmacology: Renal (Diuretics)

Flashcard 77: Lactose intolerance is characterized by a(n)_____ stool pH

Answer: decreased

Flashcard 78: Increased PCO2 (respiratory acidosis) results in _____ HCO3- reabsorption

Answer: increased

Flashcard 79: Hyperventilation as a respiratory compensation for metabolic acidosis is known as _____ breathing

Answer: Kussmaul

Flashcard 80: Distal renal tubular acidosis is associated with _____-kalemia

Answer: hypo