PA 502: Medical Physiology- Acid Base Physiology – Flashcards
44 test answers
Unlock all answers in this set
Unlock answers 44question
What are the cells of the body constantly producing?
answer
H+
Unlock the answer
question
How much H+ do healthy individuals make a day?
answer
50-100 mEq/L
Unlock the answer
question
What are the 3 ways to control pH?
answer
1. Buffer System 2. Respiratory Regulation 3. Renal Regulation
Unlock the answer
question
What is the Buffer System?
answer
-takes a strong base or acid and converts it to weak base or acid -reaction occurs within seconds -prevent changes in pH by binding H+ (acting like bases) whenever the pH of the ECF drops below normal and releasing H+ (acting like acids) whenever the pH of the ECF climbs above normal
Unlock the answer
question
What are the 3 main buffer systems?
answer
1. Bicarbonate Buffer System 2. Phosphate Buffer System 3. Protein/Amino Acid Buffer System
Unlock the answer
question
Bicarbonate Buffer System
answer
-If ECF is acidotic, weak acid created: HCL +HCO3- = HCL and carbonic acid -If ECF is alkalotic, weak base created: NaOH + carbonic acid = H2O and sodium bicarbonate
Unlock the answer
question
Phosphate Buffer System
answer
-If ECF is acidotic, weak acid created: HCL + disodium hydrogen Phosphate (Na2HPO4) = Salt (NaCl) + Sodium dihydrogen phosphate (Na2H2PO4) -If ECF is alkalotic, weak base created: Sodium Hydroxide (NaOH) + Sodium dihydrogen (NaH2PO4) + H2O and Disodium Hydrogen Phosphate (Na2HPO4)
Unlock the answer
question
Protein/Amino Acid Buffer System
answer
-If ECF is acidotic: the amine group acts as a BASE and picks up an H+ from the fluid -If ECF is alkalotic: carboxyl group acts as an ACID by donating H+ to the fluid
Unlock the answer
question
Respiratory Regulation of pH *memorize this equation!*
answer
-increases or decreases the amount of CO2 expelled from lungs depending on what is needed by the body -reaction occurs in minutes -Using the equation: CO2 + H2O H2CO3 H+ + HCO3- Hypoventilation: increased CO2, pushing the equation to the right and increased H+ concentration Hyperventilation: decreased CO2, reversing the equation to the left and decreased H+ concentration
Unlock the answer
question
Renal Regulation of pH
answer
-only process that physically removes H+ or adds HCO3- in the body -reactions occurs in hours to days -If someone is in metabolic acidosis and it won't regulate fast enough, they will die before it gets controlled -Renal Tubules Functionals in 3 ways
Unlock the answer
question
What are the 3 ways Renal Tubules function?
answer
1. Regulating H+ levels 2. Regulating HCO2- levels 3. Synthesizing HCO3-
Unlock the answer
question
Acidotic conditions:
answer
-kidneys secret H+ and reabsorb HCO3- -causes urine to become more acidic and blood more basic -Synthesizing HCO3-: renal cells lining the proximal convoluted tubule can also synthesize HCO3- to a certain extent which is then released into the blood stream
Unlock the answer
question
Alkalotic conditions:
answer
-kidneys reabsorb H+ and secrete HCO3- -causes blood to become more acidic
Unlock the answer
question
Acidemia
answer
decrease in arterial pH below 7.35
Unlock the answer
question
Acidosis
answer
condition resulting from acidemia
Unlock the answer
question
Alkalemia
answer
increase in arterial pH above 7.45
Unlock the answer
question
Alkalosis
answer
condition resulting from alkalemia
Unlock the answer
question
Arterial Blood Gases: What is this test used to assess the adequacy of?
answer
-Oxygenation, pO2 -Ventilation, pH and CO2 -Acid-Base Balance, pH, CO2, HCO3-
Unlock the answer
question
What is the normal range of pH?
answer
7.35-7.45
Unlock the answer
question
What is less that 7.35 pH considered?
answer
Acidosis
Unlock the answer
question
What is more than 7.45 pH considered?
answer
Alkalosis
Unlock the answer
question
What is a pH of less than 7.0 or more than 7.8 considered?
answer
incompatible with life
Unlock the answer
question
What is pCO2?
answer
-partial pressure of CO2 in arterial blood -the level controlled by the respiratory system -tells how the patient is ventilating normal is: 45-45mmHg
Unlock the answer
question
What is hypocarbia?
answer
less than 35 pCO2
Unlock the answer
question
What is hypercarbia?
answer
more than 45 pCO2
Unlock the answer
question
What is Respiratory Alkalosis?
answer
Increased Respirations, Decreased CO2 -causes hyperventilation (fear, pain, anxiety, crying in babies, exercise, etc.) -stimulation of respiratory center (brain injury, overdose, encephalitis, etc.) -mechanical over-ventilation
Unlock the answer
question
What is Respiratory Acidosis
answer
Decreased Respirations, Increased CO2 -hypoventilation -COPD, Pneumonia, Atelectasis- collapsed alveoli, Respiratory muscle wall weakness Mechanical under-ventilation, Barbiturate or Sedative OD, Near drowning, Suffocation (choking), Chest wall abnormality (kyphosis, obesity)
Unlock the answer
question
Metabolic Alkalosis
answer
patient is alkalotic and it is not respiratory alkalosis -accumulation of too much base -loss of too much acid -CO2 should be normal or high, >45 -HCO3- should be high >28 *If the pH is off, but the oxygen level is okay, you need to check! *excessive gastric suctioning *severe vomiting of stomach contents only *Potassium deficit *Medications: Antacids, Diuretics
Unlock the answer
question
Metabolic Acidosis
answer
-patient is acidotic and it is not respiratory acidosis -accumulation of too much acid and loss of too much base -CO2 normal or low <35 -HCO3- should be low <22 *If the pH is off, but the oxygen level is okay, you need to check! *Diabetic Ketoacidosis- body is starving, even though they do have enough glucose, body moves to ketones, Lactic Acidosis- not enough oxygen, Renal tubular acidosis, Renal failure, Severe diarrhea- body losing stool so fast, body has to replace enzymes in there, Starvation, Poisoning (e.g. methanol, ethylene glycol)
Unlock the answer
question
What is HCO3-?
answer
-measure of bicarbonate ion in arterial blood -a Base -regulated by kidneys -Normal range: 22-28 mmol/L
Unlock the answer
question
Alkalosis
answer
-leads to tissue hypoxia -causes vasoconstriction -causes O2 to bind tighter to Hgb, not released to tissues -Remember Oxygen-Hemoglobin Disassociation curve
Unlock the answer
question
pO2, PaO2
answer
-partial pressure of oxygen in arterial blood -Range 80-100mmHg, age and altitude dependent -values increase with supplemental O2 -tells how well patient is oxygenated
Unlock the answer
question
O2 Saturation, SaO2
answer
-percentage of hemoglobin actually binding, saturated with oxygen 90-100% age dependent
Unlock the answer
question
FiO2
answer
fraction inspired air that is oxygen -FiO2 of room air is 21% 2 liters = 28% 3 liters = 32% 4 liters = 36%
Unlock the answer
question
What is the FiO2 of a simple face mask?
answer
40-60%
Unlock the answer
question
What is the FiO2 of a Nonrebreather mask?
answer
60-100% (for seizures, no oxygen into their blood...)
Unlock the answer
question
What is the FiO2 of a Bag-Mask Ventilation?
answer
100%
Unlock the answer
question
Respiratory Failure
answer
pCO2 greater than 50 pO2 less than 50
Unlock the answer
question
Chronic Respiratory Failure
answer
pCO2 greater than 50, pH 7.35-7.45 pO2 less than 50, pH 7.35-7.45
Unlock the answer
question
Acute Respiratory Failure
answer
-pCO2 greater than 50, pH less than 7.35 or greater than 7.45 -pO2 less than 50, pH less than 7.35 or greater than 7.45
Unlock the answer
