Applied Physio lecture 36 (exam 3)

Flashcards covering key vocabulary and definitions related to Acid-Base Regulation.

Acid

A substance that dissociates in water to add H+ to a solution.

HA —> H+ + A-

Base

A substance that associates in water to remove H+ from a solution.

A- + H+ —> HA

Henderson-Hasselbalch Equation

An equation used to calculate pH based on the concentration of bicarbonate and carbonic acid.

It is expressed as pH = pK + log[A-]/[HA]

Bicarbonate System

The most important buffer system in the plasma that is significantly accelerated by carbonic anhydrase.

Carbonic Anhydrase

An enzyme that increases the rate of bicarbonate production by converting carbon dioxide and water into carbonic acid.

Respiratory Acidosis

A condition caused by hypoventilation leading to an increase in blood CO2 and a decrease in blood pH.

Respiratory Alkalosis

A condition caused by hyperventilation leading to a decrease in blood CO2 and an increase in blood pH.

Renal System

The body's system that adjusts bicarbonate concentration slowly but completely to regulate pH. adjusts [HCO-3]

pK

The negative logarithm of the dissociation constant which indicates the pH at which a buffer has maximum capacity.

pK = -logKD

Hypoventilation

A decrease in ventilation sufficient to increase the concentration of carbon dioxide in the blood. leads to acidosis

Hyperventilation

An increase in ventilation leading to a decrease in the concentration of carbon dioxide in the blood. leads to alkalosis

Metabolic Acidosis

A condition characterized by a decrease in blood pH due to an increase in H+ ions from non-respiratory causes.

Metabolic Alkalosis

A condition characterized by an increase in blood pH due to a loss of H+ ions or an excess of bicarbonate.

Dissociation Equilibrium Constant (KD)

A measure of the tendency of a compound to dissociate into its components in solution.

KD = [A-][H+]/[HA]

strong acids = high KD and strong bases = low KD

Chemical buffers in plasma

proteins- have a number of different pKs and can change pH over a wide range

Phosphate buffers- 1mM of plasma only, primary in cells, contributes largely to intracellular buffer capability

pH regulation through CO2 equation

pH = 6.10 + log[HCO-3]/0.0308 Pco2