Acid Base equilibrium

What is the normal pH range for a fetus?

• Between 7.25 and 7.35. (A fetal pH below 7.2 is considered acidemia).

What is the role of Carbonic Anhydrase in acid-base equilibrium?

It acts as a catalyst to speed up the buffer reaction; without it, the process is very slow.

Which buffer system is primarily used in extracellular spaces (like serum)?

• The bicarbonate buffer system.

What are nonvolatile acids?

Acids that cannot leave the body as respiratory gas and must be handled exclusively by the kidneys.

Why does diarrhea lead to acidosis?

It causes the loss of bicarbonate-rich intestinal fluid.

How can you voluntarily induce respiratory acidosis?

• By holding your breath or running without breathing, which prevents the expulsion of CO2.

What happens to bicarbonate and CO2 when new H+ (acid) is added to the system?

The system shifts to the left: H+ combines with bicarbonate to form carbonic acid, which then decomposes into water and CO2.

What is the most common cause of respiratory alkalosis?

Hyperventilation (excessive deep breathing), often triggered by anxiety, which drives down blood CO2 levels.

List three non-respiratory causes of alkalosis.

Vomiting: Loss of H+ from acidic stomach contents.

• Ingestion of bicarbonate: Consuming bicarbonate (a base) neutralizes blood H+.

• Constipation: Excessive reabsorption of bicarbonate from dehydrated feces.

How do the kidneys respond to acidosis (low pH)?

hey excrete (pee out) H+ and preserve bicarbonate to raise the pH.

How do the kidneys respond to alkalosis (high pH)?

They excrete (pee out) bicarbonate (HCO3-) to lower the pH.

What is the timeline for renal compensation to be effective?

It takes hours to kick in and days to become fully optimized.