Acid Base Balance I, II and III

Question 1

What is the normal pH value for arterial blood ?

Answer 1

7.4

Question 2

What are the 2 main sources of H ions within the body and what affect do these have on pH?

Answer 2

Respiratory Acid - Helps compensate for an increase in HCO3

Metabolic Acid - Comes from inorganic and organic acids.

Question 3

What do buffers do?

Answer 3

Minimize the changes in pH when H ions are added or removed

Question 4

Name an extracellular buffer system which is very important and state why

Answer 4

The bicarbonate buffer system
Without bicarbonate an increase in H ions would increase products and increase free H ions meaning only some of the products would be buffered.

Question 5

What is the normal PCO2 ?

Answer 5

40mmHg (5.3kPa)

Question 6

What is the ratio HCO3/H2CO3 in the blood according to the Henderson-Hasslebach equation?

Answer 6

20:1

Question 7

What is the ‘standard’ value for bicarbonate (HCO3)?

Answer 7

24mmol/L

Question 8

What does an increase in ventilation do for the bicarbonate buffering system?

Answer 8

Increases the buffering capacity?

Question 9

How is H ions eliminated from the body?

Answer 9

H is buffered until the kidneys excrete it

Question 10

Name the 4 primary intracellular buffers?

Answer 10

Proteins
Phosphates
Hb
Bone Carbonate

Question 11

When H ions move in and out of the cell, they must be accompanied or exchanged with/by which ions?

Answer 11

Cl (Accompanied) K (Exchanged)

Question 12

In acidosis what happens within the plasma that can lead to the depolarization of excitable tissues?

Answer 12

Hyperkalemia (Increase in K in ECF)

Question 13

Where is the main site of buffering of metabolic acid (ICF/ECF)?

Answer 13

43% in ECF (HCO3)

57% in ICF

Question 14

Where is the main site of buffering of respiratory acid and what is the key ICF buffer here?

Answer 14

97% in cels (Hb)

3% plasma protein

Question 15

The kidney regulates bicarbonate by which 2 mechanisms and what do they depend on?

Answer 15

Re-absorption of filtered HCO3

Generation of new HCO3

Question 16

During the mechanism for re-absorption of HCO3 what is initially secreted from the tubule cells and what is it coupled with?

Answer 16

H is secreted & it couples with HCO3

Question 17

Filtered HCO3 reacts with ____ to form_____

Answer 17

H

H2CO3

Question 18

In the presence of ________ anhydrase, ______ will disassociate to _____ and _____

Answer 18

Carbonic

H2O and CO2

Question 19

What will be found in the capillaries at the end of the HCO3 re-absorption process?

Answer 19

Na
HCO3
CO2

Question 20

What will occur is there is failure to reabsorb HCO3?

Answer 20

Metabolic acidosis (Adding H ions to ECF)

Question 21

Where does the bulk of HCO3 re-absorption take place?

Answer 21

Proximal tubule

Question 22

When there is a high amount of H ions in the urine __________ and _______ act as buffers

Answer 22

Several weak acids and bases

Question 23

The buffering of acidic urine is called what, and what does this generate?

Answer 23

Titratable acidity

Generates new Bicarbonate and excretes H ions

Question 24

In the generation of new HCO3 and ammonium excretion , _____ binds with Na and H to form______

Answer 24

NH3 NH4

Question 25

Within the _____ and _______ tubule cells ______ from the capillaries binds with water to form________

Answer 25

distal and proximal CO2 H2CO3

Question 26

The main site for the formation of new HCO3 is_____

Answer 26

Distal tubule

Question 27

Ammonium is secreted in response to what?

Answer 27

An acid load

Question 28

NH3 is _____ soluble, NH4 is not.

Answer 28

Lipid

Question 29

How is NH3 produced within the cells of the tubules?

Answer 29

Glutamine breaking down into glutamate

Question 30

Ammonia combines with what in the distal tubule lumen to generate NH4?

Answer 30

Free H ions

Question 31

NH4 is excreted alongside which ion?

Answer 31

Cl

Question 32

Where is ammonium generated in the proximal tubule, and how is it transported for excretion?

Answer 32

Within the proximal tubule cell | Through an ammonium-Na transporter on the cell surface

Question 33

Respiratory disorders mainly affect______

Answer 33

PCO2

Question 34

Renal disorders usually affect ______

Answer 34

HCO3

Question 35

Name an acute and chronic cause of respiratory acidosis

Answer 35

Acute - Obstructions of major airways and depressed respiratory centers in the brain Chronic - Lung diseases

Question 36

An increase in PCO2 will cause an _____ in HCO3, this will ______ HCO3 re-absorption

Answer 36

Increase | Increase

Question 37

What can be said about the PCO2 and HCO3 of individuals with lung disease

Answer 37

Increased PCO2 | Increased HCO3

Question 38

Name an acute and chronic cause of respiratory alkalosis

Answer 38

Acute - Voluntary hyperventilation and first ascent to altitude Chronic - Long-term residence at high altitude

Question 39

To protect ventilation in respiratory alkalosis HCO3 should _____, ______ HCO3 is produced and therefore less is _______

Answer 39

decrease less Re-absorbed

Question 40

Metabolic acidosis is when there is a decrease in what?

Answer 40

Decrease in HCO3

Question 41

Name 3 causes of metabolic acidosis

Answer 41

Loss of HCO3 (Diarrhoea) Increase in H ion production Renal failure (Inability to excrete H ions)

Question 42

Metabolic acidosis will stimulate ______ which will lower______

Answer 42

Ventilation | PCO2

Question 43

An increase in metabolic H ions would cause: Immediate ______ in the ECF and ICF _______ compensation within minutes

Answer 43

Buffering | Respiratory

Question 44

_________ compensation delays renal correction but protects pH

Answer 44

Respiratory

Question 45

In metabolic alkalosis HCO3 must have _______ and PCO2 has _____ to compensate

Answer 45

increased | Increased

Question 46

Name 3 causes of metabolic acidosis

Answer 46

Vomitting Renal H ion loss Excess HCO3 Massive blood transfusion

Question 47

How do you treat hyperkalaemia (3 Ways)? ______ (Stimulates cellular uptake of K) ___________ (Exchanges Ca ions for K ions) ______________ (Decreases excitability of the heart and stabilizes the cardiac muscle cell membranes)

Answer 47

Insulin Ca Resonium Ca Gluconate

Question 48

Hypovolaemia is the loss of _____ and water

Answer 48

NaCl

Question 49

Loss of HCl would cause metabolic ______

Answer 49

Alkalosis

Question 50

Hypovolaemia stimulates the release of which hormone from the adrenal gland? This hormone will _____ Na absorption in the distal tubule

Answer 50

Aldosterone Increase