Acid-Base Balance

Question 1

What is the normal range for pH?

Answer 1

7.35-7.45

Question 2

What is the normal range for pCO2?

Answer 2

5.1-5.5

Question 3

What is the normal range for HCO3-?

Answer 3

24-28

Question 4

What are the physiological effects of acid-base disturbance?

Answer 4

Enzymes-coagulation
Electrolyte regulation-H+/K+
Drug ionisation

Question 5

How is acid eliminated?

Answer 5

Respiratory: Ventilation removes CO2
Metabolism: Organic-liver metabolism, Inorganic-excreted by kidneys

Question 6

What are the three mechanisms involved in acid-base homeostasis?

Answer 6

1) Buffers
2) Respiratory
3) Renal (metabolic)

Question 7

What buffers are in ECF?

Answer 7

Albumin, bicarbonate

Question 8

What buffers are in ICF?

Answer 8

Haemoglobin, phosphate

Question 9

What is the main extracellular buffer?

Answer 9

Bicarbonate

Question 10

Where is the most H+ and HCO3- reabsorbed in the nephron?

Answer 10

PCT

Question 11

What state will impaired renal elimination cause?

Answer 11

Acidosis

Question 12

What is base excess?

Answer 12

The extent to which HCO3- exceeds the expected value

Question 13

What does the anion gap indicate?

Answer 13

To find whether the cause of metabolic acidosis is organic or inorganic

Question 14

What does compensation do?

Answer 14

Move the pH back towards normal

Question 15

What is the Henderson-Hasselbaclch equation?

Answer 15

pH=pKa + Log(HCO3-/H2CO3)

H2CO3 can be replaced by pCO2 due to rapid reaction from carbonic anhydrase