Acid Base Regulation

Question 1

Death due to pH

Answer 1

Below 6.8

Above 8.0

Question 2

Formation of acid

Answer 2

Most H+ ions originate from cellular metabolism

Question 3

Carbonic acid

Answer 3

Aerobic respiration of glucose
Metabolic production of CO2
CO2 + H20
about 15mol/d

Question 4

Lactic acid

Answer 4

Anaerobic respiration of glucose

Question 5

Sulfuric acid

Answer 5

Oxidation of sulphur-containing amino acids

Question 6

Acidic ketone bodies

Answer 6

Incomplete oxidation of FAs

Question 7

Phosphoric acid

Answer 7

Hydrolysis of phosphoproteins + nucleic acid

Question 8

Pathological increase of H+

Answer 8

Formic acid
Glycolic acid
Lactic acid
Acetoacetate

Question 9

Mechanisms limiting changes in pH

Answer 9

Chemical buffer system in blood + ICF - immediate
Resp centre in brain stem- 1-3 mins
Renal mechanisms - hours to days

Question 10

Buffer

Answer 10

Solution that can resist pH change upon addition of an acid or base
Acts quick to bind or release H+
Consist of weak acid + salt of that acid functioning as weak acid

Question 11

3 Major Chemical buffer systems

Answer 11

Bicarbonate
Proteins (haemoglobin + albumin)
Phosphate

Question 12

Buffer systems in ICF

Answer 12

Phosphate

Protein

Question 13

Buffer system in ECF

Answer 13

Protein

Carbonic acid

Question 14

Acidaemia + K+

Answer 14

Acidaemia leads to HYPERKALAEMIA

–> tissues release K+

Question 15

Alkalemia + K+

Answer 15

Alkalemia leads to HYPOKALAEMIA

–> cells take up K+

Question 16

ECF

Answer 16

Plasma + IF
Cations- Na+ mainly, K+ small
Anions- Mainly Cl-, some HCO3-

Question 17

ICF

Answer 17

Cations- K+ mainly, Na+ small

Anions- PO43- mainly, protein anions

Question 18

Anion gap with Na+, K+, HCO3- and Cl-

Answer 18

12-16mEq/L

Question 19

Anion gap Na+, Cl-, HCO3-

Answer 19

8-12mEq/L

Question 20

Normal gap acidosis

Answer 20

Metabolic acidosis
= hyperchloremic acidosis
Seen in loss of bicarbonate 
Reduced kidney H + excretion
Cl- increases to make up for HCO3- loss

Question 21

Normal gap acidosis causes (loss of bicarbonate)

Answer 21

Severe diarrhoea
Chronic laxative
Fistulas
Losses via NG tube

Question 22

Normal gap acidosis causes (kidney)

Answer 22

If kidney not excreting acid efficiently, more bicarbonate needed to buffer them
–> bicarbonate drop

Question 23

Elevated gap acidosis causes

Answer 23

Ketoacidosis
Lactic acidosis
Renal failure
Toxic ingestion

Question 24

Low gap acidosis

Answer 24

Haemorrhage
Nephrotic syndrome
Intestinal obstruction
Liver cirrhosis
Decreased Albumin, but increased HCO3- and Cl-

Question 25

Metabolic acidosis

Answer 25

Small increment in serum anion gap

Approx. 4-6mEq/L

Question 26

Respiratory centre/lungs

Answer 26

Second line of defence against blood pH

Lungs ONLY deal with volatile acids (CO2)

Question 27

Metabolic acid removal

Answer 27

Phosphoric, uric, lactic acid + ketones
Only kidneys can remove them
–> prevents metabolic acidosis

Question 28

Kidneys + acid balance

Answer 28

Reabsorption of all filtered bicarbonate

Excrete daily acid load

Question 29

Proximal convoluted tubule

Answer 29

Reclamation of 4500mEq of HCO3- each day

70-90%

Question 30

Daily acid excretion

Answer 30

Happens in distal kidney

Question 31

Alpha intercalated cells

distal kidney

Answer 31

Secrete acid in form of H+ ions (apical)
Reabsorb bicarbonate (basal)

Question 32

Beta intercalated cells

distal kidney

Answer 32

Secrete bicarbonate (apical)
Reabsorb Acid (basal)

Question 33

When body in alkalosis

Answer 33

Tubular cells secrete bicarbonate ions

Reclaim hydronium to acidify blood

Question 34

Henderson-Hasselbach equation- used to find

Answer 34

pH of a buffer solution

Ratio of conjugate base to acid of the system

Question 35

Henderson-Hasselbach equation

Answer 35

pH= 6.1 + log[(HCO3-)/(0.03 x PaCO2)]