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RT 105
Acid-Base and Regulation
Question | Answer |
---|---|
The normal venous pH range | 7.30 - 7.40 |
What are the 3 major systems that regulate H+ and HCO-3? | The chemical buffer system. The respiratory system. The renal system. |
Which buffer system is the first line of defense & responds w/in a fraction of a second to resist pH changes? | Chemical buffer system. |
How many minutes does the repiratory system act to acidosis or alkalosis and how does it effect the breathing depth and rate? | It takes 1-3 minutes and decreases the breathing depth and rate. |
Which system is the body's most effective acid-base balance monitor & regulator? | Renal system |
How long does it take the renal system to correct abnormal pH concentrations? | 1 day |
What does the renal system do when extracellular fluids become acidic? | It retains HCO-3 and excretes H+ into the urine, causing the blood pH to increase. |
Acids & bases are similar to salts thus they can.. | Ionize and dissociate in water & conduct an electrical current. |
Do acids retain or release hydrogen ions H+? | release |
Hydrochloric acid (HCl), the acid found in the stomach that works to aid digestion, dissociates into a proton and a chloride ion. What is the equation? | HCl --> H+ Cl- |
How do the buffers work against sudden and large changes in the pH of body fluids? | releasing hydrogen ions when pH increases and binding hydrogen ions when the pH decrease. |
Which buffer system plays an extremely important role in maintaining pH homeostasis of the blood. | carbonic acid-bicarbonate buffer system. Carbonic acid (H2CO3)dissociates reversibly and releases bicarbonate ions (HCO-3)and protons (H+) |
The carbonic acid-bicarbonate buffer system converts | Strong bases to a weak base (bicarbonate ion). Strong acids to a weak acid (carbonic acid) |
The Henderson-Hasselbalch equation | pH=pK+log[HCO3-/H2CO3] (base/acid) |
The pK is derived from... | the dissociation constant of the acid portion of the buffer combination |
Normally the pK ratio is | 6:1 |
The normal HCO3- to H2CO3 ratio is | 20:1 |
The primary components of the phosphate buffer system are the | sodium salts of dihydrogen phophate H2PO4-)and monohydrogen phosphate (HPO4-) NaH2PO4 |
NaH2PO4 - strong or weak base | weak base |
The phosphate buffer system is only about 1/ <--- as effective as the carbonic acid bicarbonate buffer system in the extracellular fluid. | 1/6 |
The body's most abundant and influential supply o buffers ___and found in the _____ | protein buffer system and found in the proteins in the plasma and cells |
Percentage of the buffering power of body fluids is found in the intracellular proteins. | 75% |
Polymers of acid | proteins |
amphoteric molecules | protein molecules that have a reversible ability are called |
A good example of a protein that works as an intracellular buffer | hemoglobin |
reduced hemoglobin carries a negative charge true or false | true |
The respiratory system does not respond as fast as the chemical buffer systems but is... | two times the buffering power of all of the chemical buffer systems combined. |
Under normal conditions, the volume of CO2 eliminated at the lung is equal to the amount of CO2 produced at the tissues. true/false | true |
When the pH declines, the repiratory system responds by increasing... | the breathing depth and rate. |
How does the respiratory system respond teh pH rises? | decreases the breathing depth and rate |
When the volume of CO2 eliminated from the lungs is less than the amount of CO2 produced at the tissue cells, respiratory acidosis is said to exist. true/false | true |
The renal system can rid the body of acids such as... | phosphoric acids ulric acids lactic acids ketone acids |
When managing the H+ levels in teh extracellular fluids, the renal system is the only system that can... | regulate alkaline substances in the blood and restore chemical buffers |
When the extracellular fluids become acidic, the renal system... | retains HCO3- and excretes H+ ions into the urine, causing the blood pH to decrease |
When the extracellular fluids become alkaline, the renal system retains | H+ and excretes basic substances into the urine, causing the blood pH to decrease |
Hypoventilation causes the partial pressure of the alvolar carbon dioxide (PAco2) to increase, which in turn causes | Pco2 increase HCO3- increase H2CO3 increase HCO3-:H2CO3 ratio decrease pH decrease |
Hyperventilation causes the partial pressure of the alveolar carbon dioxide (PAco2) to increase, which in turn causes | Pco2 decrease HCO3- decrease H2CO3 decrease HCO3-:H2CO3 ratio increase pH increase |
Common causes of acute ventilatory failure | chronic obstructive pulmonary drug overdose general anesthesia head trauma neurologic disorders |
Renal Compensation Paco2 of 70 torr pH 7.30 HCO3- 33 | acute ventilatory failure (with partial renal compensation) |
If a patient's ventilatory rate suddenly were to increase and cause the patient's Paco2 to increase to 20 torr, what approximate changes would be expected in the pH AND HCO3- levels | Acute alveolar hyperventilation (respiratory alkalosis) 7.60, 20 meq/L |
common causes of acute alveolar hyperventilation | hypoxia pain, anxiety, and fever brain inflammation stimulant drugs |
common causes of metabolic acidosis | lactic acidosis (fixed acids) ketoacidosis (fixed acids) salicylate intoxication (aspirin overdose) renal failure uncontrolled diarrhea |
plasma concentration of Na+ | 140 |
plasma concentration of Cl- | 105 |
plasma concentration of HCO3- | 24 |
an elevated anion gap is most commonly caused by the accumulation of | fixed acids |
metabolic acidosis caused by a decreased HCO3- is often called | hyperchloremic metabolic acidosis |
common causes of metabolic alkalosis | hypokalemia hypochloremia gastric suctioning or vomiting excessive administration of corticosteroids excessive sodium bicarbonate diuretic therapy hypovolemia |