Acid-Base Regulation and Blood Pressure Flashcards
(24 cards)
What is the normal pH range of blood?
7.35 to 7.45.
What is acidosis?
A condition where blood pH is below 7.35.
What is alkalosis?
A condition where blood pH is above 7.45.
What are the three lines of defense in pH regulation?
Buffers, respiratory compensation, renal compensation.
What is the most important buffer in the blood?
Bicarbonate buffer system (HCO3−/H2CO3).
How does the respiratory system regulate pH?
By regulating CO2 (acid) levels through ventilation.
How does the renal system regulate pH?
By excreting H+ and regenerating HCO3−.
What is respiratory acidosis?
Low pH due to CO2 retention (e.g., hypoventilation).
What is metabolic acidosis?
Low pH due to HCO3− loss or H+ gain (e.g., diarrhea).
What is respiratory alkalosis?
High pH due to CO2 loss (e.g., hyperventilation).
What is metabolic alkalosis?
High pH due to H+ loss or HCO3− gain (e.g., vomiting).
What causes metabolic acidosis?
Diarrhea, renal failure, lactic acidosis.
What causes respiratory alkalosis?
Hyperventilation (e.g., anxiety, altitude).
How does the kidney respond to acidosis?
Increase H+ excretion and HCO3− reabsorption.
How does the kidney respond to alkalosis?
Decrease H+ secretion and increase HCO3− excretion.
Where does H+ secretion primarily occur in the nephron?
Proximal and distal tubules.
What is the role of ammonia in acid-base balance?
Buffers H+ in urine and allows H+ excretion as NH4+.
What are titratable acids?
Buffered H+ in phosphate or sulfate excreted in urine.
What is effective circulating volume (ECV)?
The part of extracellular fluid that perfuses tissues and organs.
How does low ECV affect renin release?
It increases renin secretion from the juxtaglomerular cells.
What effect does aldosterone have on potassium?
Promotes K+ excretion in exchange for Na+ reabsorption.
What hormones increase sodium and water reabsorption?
Aldosterone, angiotensin II, ADH.
How does ANP affect blood pressure?
Reduces blood pressure by promoting Na+ and water loss.
What is the role of the hypothalamus in volume regulation?
Regulates thirst and ADH release.
