Acid-base balance

Question 1

What is an acid?

Answer 1

H+ donor

Question 2

What is a base?

Answer 2

H+ acceptor

Question 3

What is a weak acid/base?

Answer 3

partially dissociates

Question 4

What is a strong acid/base?

Answer 4

fully dissociates

Question 5

What is a buffered solution?

Answer 5

a solution in which the addition of an acid or base does not affect the pH of the solution

Question 6

How do buffers work?

Answer 6

buffers are weak acids or weak bases
the conjugate base of the partially dissociated weak acid neutralises added acid
the hydrogen ion from the partially dissociated weak base neutralises added alkali

Question 7

Name some physiological buffers

Answer 7

bicarbonate
phosphate
plasma proteins
haemoglobin

Question 8

Define acidaemia, alkalaemia, acidosis and alkalosis

Answer 8

acidaemia = an arterial pH below the normal range (<7.35)

alkalaemia = an arterial pH above the normal range (pH>7.45)

acidosis = a process that tends to lower the extracellular fluid pH (add H+ ions)

alkalosis = a process that tends to raise the extracellular fluid pH (remove H+ ions)

Question 9

Why are buffers important in the urine?

Answer 9

if no buffers existed in urine then in order to eliminate ~70mmol of H+ the kidneys would need tp excrete 700L of urine a day

Question 10

Urine anion gap equation

Answer 10

[urine Na+ + urine K+] - urine Cl-

Question 11

What does a negative urine anion gap in metabolic acidosis mean?

Answer 11

means tubular function is intact and metabolic acidosis is extrarenal

Question 12

Respiratory acidosis causes

Answer 12

emphysema
hypoventilation
laryngeal oedema

Question 13

Metabolic acidosis causes

Answer 13

lactic acidosis
renal tubular acidosis
renal failure
ketoacidosis

Question 14

Respiratory alkalosis causes

Answer 14

congestive cardiac failure
raised intracranial pressure
hyperventilation

Question 15

Metabolic alkalosis causes

Answer 15

vomiting
diuretics
Conn’s syndrome