acid / base - patho 406

Question 1

pH

Answer 1

the potential or power of hydrogen
the negative logarithm of the hydrogen ion -> when H+ goes up, pH goes down

Question 2

acid substances can “” an H+ ion & alkaline substances can “” an H+ ion and “” an OH-

Answer 2

give ; accept ; give up

Question 3

why is hydrogen important to the body

Answer 3

-helps maintain cell membranes
-helps w/ enzyme activity
-component of H2O
-helps energy production

Question 4

hydrogen is a component of

Answer 4

sugars
proteins
starch
fats

Question 5

what does a neutral acid-base balance mean

Answer 5

-pH=7
-equal H+ & OH-

Question 6

pH goal range

Answer 6

7.35 - 7.45
pH is not the same through the body

Question 7

what happens if the body’s pH is not within goal range

Answer 7

-enzymes malfunction
-electrolyte imbalances (esp K+)
-O2 transport & delivery can be affected

Question 8

if the body is more acidic, hemoglobin will

Answer 8

give up oxygen more readily at the tissue

Question 9

if the body is more alkalotic, hemoglobin will

Answer 9

hold on to the oxygen and not give it to the tissue
a bigger problem then if the pt is more acidic

Question 10

what pH is incompatible to life

Answer 10

below 6.8 d/t profound effect on cellular metabolism, enzyme activity and oxygen delivery to the tissue

Question 11

if the pH is above 7.8

Answer 11

life threatening -> disrupts essential bodily functions, particularly in the cardiovascular and nervous system

Question 12

what are the two types of acids in the body

Answer 12

volatile & non volatile

Question 13

volatile acids

Answer 13

-can be converted to gas
-excreted/eliminated by the lungs
-one volatile acid in body (carbonic acid H2CO3 -> H2O + CO2)
allows lungs to expel carbon dioxide

Question 14

non volatile acids

Answer 14

-lactic acid (met by kid/liv, can be reconverted & used as energy production if needed)
-phosphoric acid (bones & kidney support)
-sulfuric acid (produced w/ protein met)
-acetoacetic acid (produced in liver)
-beta hydroxybutric (inc w/ exercise, calorie restrictions, fasting & dx of ketoacidosis)
will all be eliminated by kidney (expect lactic acid) & cannot be converted to a gas

Question 15

lactic acid is a byproduct of what

Answer 15

anaerobic metabolism

Question 16

at baseline, does the body produce more acids or bases

Answer 16

acids b/c we eat/drink more acidic foods, the metabolism of lipids & protein generate acids and cellular metabolism waste product is CO2 which makes volatile acid

Question 17

how does the body maintain acid - base homeostasis

Answer 17

-buffers: works all the time & is immediate
-respiratory system: rapid but short lived
-renal system: long term balance

Question 18

buffers

Answer 18

-chemicals in the body that combine w/ acid or bases to change the pH
-accept or release a H+
-almost instantaneous but short lived
3 main systems: bicarbonate - carbonic acid buffer, phosphate buffer & protein buffers (hemoglobin)

Question 19

Bicarbonate - Carbonic Acid

Answer 19

-main buffer seen outside the cell in the ECF
-carbonic anhydrase breaks down carbonic acid, if in the lungs this allows for CO2 to be expelled & if it is in the kidneys then will break down into H+ + HCO3- and the kidneys can excrete the hydrogen ions

Question 20

if a patient is in the ICU and is acidic & not compensating, what can we give

Answer 20

sodium bicarb to raise their pH

Question 21

Bicarbonate - Carbonic Acid equation (need to know)

Answer 21

HCO3- (bicarb) + H+ <-> H2CO3 (carbonic acid)<-> CO2 + H2O
if we retain CO2, equation will work in the direction of increases bicarb (think COPD or resp depression
kidneys can generate bicard & rid H+, lungs can expel CO2

Question 22

phosphate buffer

Answer 22

main intracellular buffer
H+ +HPO4-2 = H2PO4- (example of buffer picking up a H+ ion intracellularly to balance pH)

Question 23

Protein Buffers

Answer 23

-nearly all proteins can function as buffers
-carboxyl group (COOH) is a weak acid that gives up H+ (ex: amino acids & acetic acid)
-amino group (NH2-) accept H+
-hemoglobin picks up CO2 at the cellular level which results in less CO2 to make carbonic acid

Question 24

cellular compensation

Answer 24

pH decreases -> H+ move into the cell creating more positively charged ions in the cell -> K+ moves out of the cell to maintain a neutral charge since it is also a + ion -> electrical neutrality is restored inside the cell
process will reverse as pH neutralizes & H+ will move out of the cell and K+ will move back into the cell

Question 25

main concern w/ cellular compensation

Answer 25

K+ will be moved out of the cell and if it cannot be excreted through the kidneys, dysrhythmias can occur or if too much get excreted which can also cause a dysrhythmias

Question 26

respiratory mechanisms to maintain pH homeostasis

Answer 26

when carbonic acid reaches the lungs it will break back into water and CO2 which will be expelled so body can adjust pH by changes rate & depth of breathing (inc will blow off more CO2 if pt is acidic, dec if patient is alk)
does not work for non volatile acids

Question 27

kidney regulation maintain pH homeostasis

Answer 27

long term adjusters, adjusts the amount of HCO3
-can eliminate large amounts of acid expect carbonic acid & can also excrete base (when pH is too basic)
-can conserve & produce new bicarb ions (when pH is too acidic)
-most effective regulator of pH
-if kidney fails, pH balance fails

Question 28

if a patient is in renal failure, what do they usually have to take daily

Answer 28

sodium bicarb to regulate their pH

Question 29

kidney regulation: acidosis

Answer 29

kidneys respond by increasing reabsorption of bicarb (& making new) and increasing secretions of hydrogen ions (acid component) into the urine. this helps raise pH back to normal

Question 30

kidney regulation: alkalosis

Answer 30

kidney respond by decreasing bicarb reabsorption and reduce hydrogen ion into urine. This helps lower the pH back to normal

Question 31

rates of correction

Answer 31

Buffers: instantaneously
Respiratory: several minutes to hours
Renal: several hours to days

Question 32

compensation

Answer 32

if underlying problem is metabolic, hyperventilation or hypoventilation can help aka respiratory compensation

If underlying problem is respiratory, renal mechanisms can bring about metabolic compensation

Question 33

normal CO2

Answer 33

35-45

Question 34

normal pO2

Answer 34

80-100

Question 35

normal HCO3

Answer 35

24-29

Question 36

normal O2 stat

Answer 36

95-100%