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Are the primary acid-excreting organs.
Lungs and kidneys
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These excrete volatile (CO2) to lower H2CO3
Lungs
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Removes H+ rom the body.
Kedneys
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Eliminating of substances from the body in the urine.
Excretion
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The process by which blood substances diffuse into renal tubule cells, whuch they actively transport them into the fluid (filtrate) within the tubular cell.
Secretion
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The active or passive transport of filtrate substances back into the tubule cell, and then into the blood of nearby capillaries
Reabsorption
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Regulates the excretion of H+ ions and the reabsorption of HC)3- ions.
Basic Kidney Function
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There is high blood CO2, Acidic pH, and high level of H+
Hypoventilation
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The kindneys will try to reabsorb all filtrate HCO3 in the blood when this happens.
Hypoventilation
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Low blood CO2, Alkaline pH, and low level H+.
Hyperventilation
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The kidneys will try to increase the quantity of HCO3- in the urine when this happens.
Hyperventilation
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If no buffers existed in the filtrate to react with H+, the seceting mechanism will?
Cease to function
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Any extra H+ remaining after the bicarbinate bufffers are exhausted, will react with two other filtrate bufer:
Phosphate and ammonia
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This buffer show up with excess H+, allows the kidneys to further increase their excretion of H+ ions, combines w/ excess H+ to form H2PO4-, and Na+ and HCO3- are reabsorbed in exchange for H+ ions.
Phosphate buffer
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In responce to low filtrate pH, allows for elimination of H+ and C- ions w/o effecting the urine pH.
Ammonia Buffer
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A chloride is excreted in the urine, a _______is gained.
Bicrabonate HCO3
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These secrete ammonia in responce to low-filrate pH.
Tubule Cells
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normal PaCO2 range
35-45mmHg
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normal HCO3- range
22-26mEq/L
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Normal acid base balance.
20:1
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is when the blood pH is greater than 7.45
Alkalemia
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is when the blood pH is less than 7.35
Acidemia
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is when PaCO2 is less than 35 mmHg
hyperventilation
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is when PaCO2 is greater than 45 mmHg
Hypoventilation
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changes in pH caused by change in PaCO2.
Primary Respiratory Disturbance
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pH decreased, PaCO2 increased, HCO3 is normal.
Resp. Acidosis (hypovent)
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pH increased, PaCO2 decreased, HCO3 is normal.
Resp. Alkalosis (Hypervent)
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Change in pH due to gain or loss of fixed acids or HCO3
Primary Metabolic Disturbances
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pH decreased, PaCO2 is normal, HCO3 is decreased.
Metabolic acidosis
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pH is increased, PaCO2 is normal, HCO3 is increased.
Metabolic alkalosis
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This is restoring pH to normal. The body will initiate this respoce to any primary acid-base defects.
Compensation ( compensatory responce)
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the kidneys will restore pH toward normal by reabsorbing HCO3 into the blood when this is happening.
Repisatory acidosis (hypovent.)
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the kidneys will eliminate HCO3 in the urine when this is hapening.
Respiratory alkalosis (hypervent.)
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the lungs will compensate by hyperventilating when this occurs.
metabolic acidosis
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the lungs will compensate by hypoventilating when this is occuring.
metabolic alkalosis
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Arterial HCO3 does increase slightly as the PaCO2 rises, because the CO2 hydration reaction generates HCO3. THis happens due to a RBC catalytic enzyme called?
Carbonic anhydrase
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Rule of thumb: if the PCO2 increases acutely, the plasma [HCO3] rises _____ mEq/L for every 10 mmHg increase in PCO2 above _______.
1 mEq/L 40 mmHg
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Systematic Acid-Base Classification: Step 1
Categorize the pH
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Systematic Acid-Base Classification: Step 2
Determine Respiratory involvement
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Systematic Acid-Base Classification: step 3
determine metabolic involvement
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Systematic Acid-Base Classification: step 4
assess for compensation
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increased PaCO2 is synonymous with respiratory acidosis.
hypercapnia
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Any process on whcih alveolar ventilation fails to eliminate CO2 as rapidly as the body produces it.
Causes of Resp. Acid.
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Compensation of Resp. acid.?
kidney reabsorbs HCO3
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has a high PaCO2, a High HCO3, and an acid pH not quite in normal range.
part. comp. resp. acid.
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characterized by a pH on the acid side of normal range >/= 7.35 by <7.40 ex: pH 7.35 PCO2 55 HCO3 32 BE +4
fully comp. resp. acid.
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How can you correct acidosis?
Improve alveolar ventilation
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Various repiratory care modalities for improving alveolar vent.
bronchial hygiene breathing manuevers, endotracheal intubation, and mechanical ventilation
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if hypventilation is chronic, rapidly reducing PCO2 to normal is?
inappropriate and harmful.
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a low PaCO2 is sysnonmous with respiratory alkalosis.
hypocapnia
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any process in which ventilary elimination of CO2 exceeds its production causes.
resp. alk.
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Clinical signs: paresthesia, severe hyperventilation, hyperactive reflexes, tetanic convulsions, low PaCO2
Resp. Alk.
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characterized by a low PaCO2, a low HCO3 and an alkaline pH- not quite in the normal range.
part. comp. resp. alk.
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characterized by a low PaCO2, low HCO3, and a pH on the alkaline side of normal (> 7.4 but = 7.45)
fully comp. resp. alk.
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Removing the stimulus causing hyperventilation is a correction for what?
Respiratory Alkalosis
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the number one cause for Respiatory alkalosis is?
hypoxemia
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Reference pg 294 for all causes and 298.
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