Acid Base Homeostasis

Question 1

Kassier-Bleich Equation

Answer 1

[H+] = 24 (PCO2)/[HCO3-]

Question 2

What is the normal pH in the body?

Answer 2

7.4

Question 3

How do you calculate pH?

Answer 3

-log[H+] with H+ in moles

Question 4

What happens to pH when H+ increases?

Answer 4

pH decreases!

Question 5

How much H+ do we have in our gut?

Answer 5

100 mM

Question 6

How much H+ do we have in our plasma?

Answer 6

40 nanomoles

Question 7

What can pH range between?

Answer 7

4-8

Question 8

What is the Isohydric Principle?

Answer 8

If you change the [H+], you change every one of those acid-base pairs in your system/body.

Question 9

What different proteins do you have in your body? What is the significance of these proteins?

Answer 9

• DNA, WOA, Carbohydrates
• You can add or subtract a charge/H+ from the protein
• -> This will change its ionization and alter the fundamental way it will behave

Question 10

What does altering H+ concentration do to your proteins?

Answer 10

It alters their conformation, can change their charge and will make them overall less functional

Question 11

What is Le Chatelier’s Principle?

Answer 11

“Equilibrium Law” - Any system at equilibrium, when disturbed, will adjust itself to (partially) counteract the disruption. == It re-establishes a new equilibrium

Question 12

What is Acidemia/Alkalemia?

Answer 12

An increase or decrease in H+ ions representing a change in pH. Tells nothing about cause.

Question 13

What is Acidosis/Alkalosis?

Answer 13

Description, either metabolic or respiratory, of the process that leads to the acidemia or alkalemia

Question 14

What is a buffer?

Answer 14

-We have a huge capacity to buffer our pH using our bicarbonate levels
System seen many times:
CO2 + H2O H2CO3 H+ + HCO3-

Question 15

What controls the buffering equation?

Answer 15

Carbonic anhydrase (bicarb equation)

Question 16

What are the physiologic consequences of Acidosis?

Answer 16

• Inc. respiration (to blow off CO2)
• Kussmaul breathing: Deep, slow labored breaths
• Depresses cardiac contractility (below pH 7.2)
• Increases circulating catecholamine levels
• Stimulates protein catabolism, leading to negative nitrogen balance
• Leads to bone loss (removal of HCO3- for buffering)

Question 17

What are the physiologic consequences of Alkalosis?

Answer 17

• Hypoventilation
• Cardiac arrhythmias (particularly above a pH of 7.5)
• Shifts oxygen dissociation curve to the LEFT, thereby decreasing oxygen delivery to tissues
• Increased lactate production

Question 18

What are Respiratory issues derived from?

Answer 18

Respiratory problems!

Question 19

How are respiratory issues compensated?

Answer 19

By the kidney

-It does this slowly over a period of days

Question 20

What are Metabolic issues derived from?

Answer 20

Non-respiratory issues

diarrhea, RTA

Question 21

How are metabolic issues compensated?

Answer 21

Lungs compensate –> they do this in minutes

Question 22

What is loss of bicarbonate equivalent to?

Answer 22

Addition of acid