General Acid/Base Balance - Checked and Complete

Question 1

What is the pH range compatible with life?

Answer 1

** 6.8 to 7.7**

Question 2

What is the typical pH of intercellular fluid?

Answer 2

7.0

Question 3

What are sources of body acid?

Answer 3

1) Carbonic acid (CA) formed from H₂O and CO₂

2) Non-carbonic acids (HNC) - sulfuric and phosphoric acids from the metabolism of proteins and lipids

3) Acid metabolic intermediates: lactic acid and ketones

4) Acids from diet

Question 4

What are common sources of acid/base imbalances?

Answer 4

Lung problems

Kidney problems

Loss of acidic vomit

Loss of alkaline diarrhea

Question 5

What are usual forms of compensation during acid/base imbalances?

Answer 5

Change lung respiration to affect CO₂ concentration

Change kidney reabsorption of bicarb

Question 6

List examples of body buffering systems

Answer 6

1) MAIN = Carbonic Acid buffering system (HCO₃^- /H₂CO₃)

2) Hemoglobin (Hb^- /HHb)

3) MAIN ICF buffering = proteins (Pr^- /HPr) and phosphates (HPO₄ ^2-/H₂PO₄^-)

4) Plasma proteins (Pr^- /HPr)

5) Bone CO₃^2- release during acidosis

Question 7

Provide time ranges for how long it takes body buffers to act.

Answer 7

Carbonic acid = Minutes

Hemoglobin = Minutes

Intracellular proteins and phosphates = Hours

Bone Carbonate = Hours-Days

Question 8

How is the Carbonic Acid System buffered?

Answer 8

CA is only buffered by HNC buffers. The CA system cannot buffer itself.

Question 9

Describe how the body handles hypoventilation

Answer 9

P_CO2concentration increases and forms extra Hydrogen ions

Hemoglobin binds these extra hydrogen ions

The kidney later adds new bicarb to the body and reverses the reaction, allowing Hydrogen ions to dissociate from Hemoglobin

Question 10

Describe handling of an HNC (non-carbonic acid) to the blood via metabolism such as lactic acid or ketones

Answer 10

1) Buffered in plasma and interstitium by bicarb

2) Buffered intracellularly by proteins/phosphates

3 )CO₂ blown off after sensed by peripheral chemoreceptors

4) Kidney produces more bicar and excretes Hydrogen ions

Order of speed at buffering:

ECF buffering quickest

ICF buffering next

Respiratory compensation slower

Renal compensation slowest

Question 12

What is the normal Hydrogen ion concentration of body fluids?

Answer 12

40nM is normal ECF

100nM is normal ICF

20-160nM is livable range