A Aand P Ch 20 Acid Base Balance Flashcards
Most important homeostatic mechanisms
Acid base balance
What does pH mean
Power of hydrogen in a solution
WHat does pH measure
The acid or base character of a solution
What is the pH or pure water
- = neutral. Less than 7 is acidic
Acidic substances
Lemon juice. Vinegar. Hydrochloric acid (stomach acid)
Acid in Latin
Sour
Which substance in the body has the lowest pH
The stomach
Which substance has the highest concentration of hydrogen ions
Lemon juice has a very high concentration hydrogen ions
pH is represented on a scale from 0 to 14 what is neutral on the scale?
- Less than 7 is acidic more than 7 is basic
The higher the pH the fewer the
Hydrogen ions
Which feels slippery like soap acid or base
Base
Buffer can be either or
Acid or alkaline
HCO3 represents
Bicarbonate (buffer)- basic solution
Will buffer acid-weaken the acidity
pH of normal arterial blood
7.45
Normal pH of venous blood
7.35
Normal pH range of human blood
7.35 to 7.45
Balance is achieved when pH is in this range
What is bodies mechanism for self regulation of pH. (2 ways)
Respiratory mechanism (quick response)
Urinary mechanism (can help with regulating in 24 hours)
Whai is Acidosis and alkalosis
PH inbalances
Acid base or pH imbalance depends on
How much carbonic acid (weak solution) H2CO3 in blood
How much sodium bicarbonate (NaHCO3) in the blood
Body regulates both through homeostatic buffer system
Sodium bicarbonate is regulated by (NaHCO3)
Kidneys
Carbonic acid (H2CO3) is regulated by
Lungs
What do the lungs Exhale and how much
Carbon Dioxide, eliminating carbonic acid from venous blood
30L daily
What will eventually happen With a significant decrease in breathing
Acidosis
What will eventually happened with an excessive increase in breathing
Alkalosis
Most effective regulator of pH
Kidneys
How does urine become acidic
Kidneys secrete hydrogen ions and ammonia NH3 from blood and into urine
Reabsorbs sodium bicarbonate (NaHCO3) into blood
More acids than bases usually enter blood causing the kidneys to
Excrete more acids than bases
Ratio of sodium bicarbonate (NaHCO3) to carbonic acid (H2CO3)
20:1
If buffering increases amt of carbonic acid in blood, what happens to sodium bicarbonate
It’s amt decreases in the blood
If hydrogen concentration of blood increases slightly, than blood pH in blood does what
PH decreases (acidic), than buffering system kicks i
Which buffer system is fast
Respitory
Slowest buffering system
Renal/kidney
If Respiratory mechanism fails, then
The more powerful, but, slower renal mechanism kicks in
What is Respitory mechanism of pH control
Respiration remove some CO2 from blood
Bl flows thru lung capillaries and amt of carbonic acid is decreased therefore hydrogen concentration
Is decreased
Do kidneys regulate carbonic acid
No carbonic acid is regulated by lungs
Metabolic and respiratory IMBALANCES are
PH imbalances causing 20:1 ratio to be disturbed
Metabolic disturbances affect bl levels of
sodium bicarbonate
Respitory disturbances affect bl levels of
Carbonic acid
Metabolic pH imbalance of
Metabolic acidosis is too little
Sodium bicarbonate
Metabolic imbalance
Metabolic alkalosis is too much (complication of severe vomiting)
Sodium bicarbonate
Respitory alkalosis is deficit of
Carbonic acid
Respitory acidosis is too much
Carbonic acid
AnExample of a Respitory disturbance
Hyperventilation=Deficit of carbonic acid
Caused by excessive loss of CO2 in expired air

In acidosis or alkalosis the various pH mechanisms try to restore balance
As soon as possible because
Compensation is clinically important
You can have a serious ongoing medical condition while having what appears to be a normal pH
Uncompensated metabolic acidosis changes
The normal ratio of 20 to 1
In Compensated metabolic acidosis The ratio of Sodium bicarbonate to carbonic acid Remains close to 20 to 1, what changes is
The TOTAL amount of sodium carbonic and carbonic acid