Acid-Base Interactive Tutorial.

Acid-Base Pretest:  What is the normal range for arterial blood pH? 7.38 – – – 7.45

Correct!  This is the correct parameters for arterial blood pH with the extracellular fluid in the middle at 7.40… well done! Next QuestionPrevious Question

Acid-Base Pretest:  What 2 extracellular substances work together to regulate pH? Sodium bicarbonate & carbonic acid Carbonic acid & bicarbonate Acetic acid & carbonic acid

Correct!  Right on! Carbonic acid and bicarbonate are the two primary extracellular regulators of pH. pH is also further regulated by electrolyte composition within the intra & extracellular compartments. Next QuestionPrevious Question

Acid-Base Pretest:  Characterize an acid & a base based on the choices below. Acids release hydrogen (H + ) ions & bases accept H + ions. Acids accept H + ions & bases release H + ions Both acids & bases can release & accept H + ions

Correct!  Acids are molecules that have the ability to release H + ions & bases are molecules that have the ability to accept or bind with H + ions. Next QuestionPrevious Question

Acid-Base Pretest:  Buffering is a normal body mechanism that occurs rapidly in response to acid- base disturbances in order to prevent changes in what? HCO 3 - H 2 CO 3 H+H+

Correct!  Excellent! H + ion concentration is most important to regulate in order to prevent acid-base balance disturbances. Next QuestionPrevious Question

Acid-Base Pretest:  What are the two systems in the body that work to regulate pH in acid-base balance & which one works fastest? The Respiratory & Renal systems Renal The Respiratory & Renal systems Respiratory The Renal & GI systems Renal

Correct!  Great work! Both the respiratory & renal systems work to regulate pH in acid- base imbalance; the respiratory system works in a matter of minutes & is maximal within hours while the renal (kidneys) system continues to function for days to restore pH within normal limits (WNL). End PretestPrevious Question

Acids and Bases can be strong or weak:  A strong acid or base is one that dissociates completely in a solution dissociates - HCl, NaOH, and H 2 SO 4HCl, NaOH, and H 2 SO 4  A weak acid or base is one that dissociates partially in a solution -H 2 CO 3, C 3 H 6 O 3, and CH 2 OH 2 CO 3, C 3 H 6 O 3, and CH 2 O

Protein Buffer Systems:  Largest buffer system in the body  Amphoteric: can function as acids or bases  Contain several ionizable groups able to bind or release H +  Largely located in cells; H + & CO 2 diffuse across cell membranes for buffering by Albumin & plasma globulins Albumin & plasma globulins Previous Slide

Bicarbonate Buffer System:  Uses NaHCO 3 as its weak base & H 2 CO 3 as its weak acidNaHCO 3H 2 CO 3  The HCO 3 - /CO 2 buffer system can readily add or remove components from the body  An ample supply of CO 2 provided via metabolism, replaces H 2 CO 3 lost when excess base is added  In turn, the kidneys conserve or form new HCO 3 - in the presence of excess acid & excrete HCO 3 - in the presence of excess base Previous Slide

Quick Review: Click the Boxes A donator of H + ionsAn acceptor of H + w/ pH 7.0 Regulated by EC Controlled by EC H 2 CO 3 & HCO 3 - & IC buffer systems Eliminates CO 2 Conserves HCO 3 - Eliminates H + ions An Acid is:A Base is: pH is: Respiratory System: pH is: Renal System:

The Phosphate Buffer system:  Uses HPO 42 - and H 2 PO 4 - present in tubular filtrateHPO 42 - and H 2 PO 4 -  Both become concentrated in the fluid due to relatively poor absorption & reabsorption of H 2 O from tubular fluid  H + combines w/ HPO 42 - to form H 2 PO 4 - giving the kidneys the ability to increase secretion of H + ions  When H + ions in the bloodstream decrease, pH increases & vice versa  Subsequently hydrogen phosphate either accepts or releases H + ions to maintain pH within the bloodstream Previous Slide

The Ammonia Buffer System:  This buffer system is the more complex of the two  The generation of HCO 3 - & excretion of H + by this system occurs in 3 steps: 1) synthesis of NH 4 + from glutamine, an amino acid in the proximal tubule, thick ascending loop of Henle & distal tubulesNH 4 +proximal tubulethick ascending loop of Henle distal tubules 2) recycling & reabsorption of NH 3 in the kidney’s medulla, &NH 3 3) buffering of H + ions by NH 3 in the collecting tubules. Previous Slide

Acid-Base Balance Review test:  The kidneys regulate pH by excreting HCO 3 - and retaining or regenerating H + TRUE FALSE

Incorrect  Actually the kidneys work to regulate pH through the regeneration or reabsorption of HCO 3 - & excretion of H + Next QuestionPrevious Question

Correct!  You’re absolutely right! The kidneys actually do the opposite in order to regulate pH. Nicely done. Next QuestionPrevious Question

Acid-Base Review test:  H 2 CO 3 splits into HCO 3 - & H + & it is the H + that stimulates either an increase or decrease in the rate & depth of respirations. TRUE FALSE

Correct!  You got it! This is because H +, along with CO 2 in the blood stream, act directly on respiratory centers in the brain. Next QuestionPrevious Question

Incorrect  The correct answer is TRUE. Please review the Respiratory Control Mechanisms slide as needed. Next QuestionPrevious Question

Acid-Base Review test:  Plasma concentration of HCO 3 - is controlled by the kidneys through reabsorption/regeneration of HCO 3 -, or elimination of buffered H + via the tubular systems. TRUE FALSE

Correct!  Yes! Reabsorption of filtered HCO 3 - or generation of new HCO 3 - & or H + ion elimination via phosphate & ammonia buffer systems help the kidneys regulate plasma concentrations of HCO 3 -. Next QuestionPrevious Question

Incorrect  Please review Mechanisms of Acid-Base balance if needed. Next QuestionPrevious Question

Acid-Base Review test:  The ratio of H + to HCO 3 - determines pH. TRUE FALSE

Incorrect  The answer is false. It’s the ratio of HCO 3 - to volatile H 2 CO 3 that determines pH. Next QuestionPrevious Question

Correct!  You’re right, the answer is false. REMEMBER: concentrations of volatile H 2 CO 3 are regulated by changing the rate & depth of respirations. Next QuestionPrevious Question

Acid-Base Review test:  Secreted H + couples with filtered HCO 3 - & CO 2 & H 2 O result. TRUE FALSE

Correct!  Well done! If you look back at the H + Elimination & HCO 3 - Conservation slide, this is part of the Na + /H + transport system. End Post testPrevious Question

Incorrect  Sorry, but the correct answer is true. End Post testPrevious Question