Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.

Remove ads
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards




share
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

108 Unit 2

Acid-Base Physiology

TermDefinition
Hydrogen Ion Activity -efficient biochemical and enzymatic processes demand an exacting cellular environment -Free [H+] is measuered in plasma
Hydrogen Ions -among most important factors in the cellular environment -affect all physical and biochemical cellular phenomena -increases acidic value of solution
pH stands for -Power of hydrogen -Potential Hydrogen -Logarithmic value of the reciprocal of the [H+] -4 x 10^8 moler per liter (.00000004)
Ways to Express pH - - log (4 x 10^8) or (0.00000004) - -(-7.3979) - 7.40 (normal)
3 Descriptions of pH - [H+] -Negative log of the [H+] -Log of the reciprocal of the [H+] or inversely proportional to the [H+]
Components that affect the pH -Respiratory Component (PCO2) -Metabolic Component (HCO3-/Bicarb)
Respiratory Component (PCO2) -acid -pCO2 has an inverse affect on pH -increased pCO2 increases the acidic value of a solution [H+]
Metabolic Component (HCO3-/Bicarb) -base -HCO3- has a direct affect on pH -increased HCO3- increases alkalotic (basic) value of solution [H+] -HCO3- wants to bind to hydrogen so it eliminates free floating H+
Acids donate hydrogen ions (protons)
Bases accept hydrogen ions (protons)
Metabolism Aggregate of all chemical processes that result in: -growth -energy production -elimination of waste -other bodily functions as they relate to the distribution of nutrients in th blood after digestion
Two phases of Metabolism -Catabolism -Anabolism
Catabolism -destructive phase -larger molecules are converted to smaller molecules -decomposition reactions -breaks down nutrients -produces energy (exergonic)
Anabolism -constructive phase -smaller molecules are converted to larger molecules (synthesis) -growth and repair -consumes energy (endergonic)
What does Metabolic Rate Determine? -quantity of CO2 produced and enters the blood
What does Lung Function Determine? -quantity of CO2 excreted from the blood
Sources of Energy -Carbohydrate Metabolism: Main source of energy -Lipid/Fate Metabolism: used if carb metabolism is deficient -Protein Metabolism: "last resort energy"
Carbohydrate Metabolism -final products of digestion include glucose, fructose, and galactose
Glucose -95% of blood sugars produced -stored as glycogen or fat -converted back to glucose as needed -carried through cell membranes by proteins that are aided by insulin
Glycolysis -metabolic pathway that converts glucose to energy -aerobic metabolism -anaerobic metabolism -CO2 is a waste product
Aerobic Metabolism yields what? -pyruvic acid
What does Anaerobic Metabolism yield? -lactic acid
Incomplete oxidation of Carbohydrates -can be caused by stress & Exercise -both aerobic and anaerobic metabolism yield ATP and H+ -H+ are used in oxidative phosphorylation to produce more HTP
What can reverse Incomplete Oxidation of Carbohydrates? -increased O2 -Decreased activity -Decreased metabolism
Iipids(fats) Metabolism -fats are stored or used as energy for the body -if carbohydrate metabolism is deficient, more fat will be used -Acetoacetic Acid (typd of keto acid) is waste product
Protein Metabolism -O2 transport -Enzyme function -Aid in muscle contraction -catabolized into amino acids -used as a last resort for energy -NH3 (ammonia) is a key waste product
Respiratory Quotient (RQ) CO2 produced/O2 consumed -80% is normal
What accounts for nearly all the O2 consumption of the body? -Oxidation of carbohydrates and fats -major sources of energy for the body
Metabolism of Carbohydrates RQ -1 mole O2 consumed -1 mole CO2 produced -RQ = 100%
Metabolism of Fats RQ -1 mole of O2 consumed -0.7 moles CO2 produced -RQ = 70%
Metabolism of Proteins RQ -1 mole of O2 consumed -0.7 moles of CO2 produced -RQ = 70%
Where is CO2 carried? -plasma 5% -RBC 95%
Plasma CO2 -dissolved CO2 accounts for most CO2 carried in plasma -0.1% reacts with water for form H2CO3 (hydrolysis or hydration) -difficult to distinguish between dCO2 and H2CO3
Plasma CO2 Hydrolysis equation -very slow -carbonic anydrase (enzyme) is not present
Total dCO2 plasma PCO2 x 0.003
Solubility coefficient of CO2 0.003
Total dCO2 -value used to represent H2CO3 in Henderson-Hasselbach equation
Dissolved CO2 accounts for 8% of total CO2 released in the lungs
CO2 Transport in the RBC -80% of CO2 is transported as bicarbonate (HCO3-) -hydrolysis occurs very rapidly due to carbonic anhydrase -12% of CO2 chemically combines with amino acids contained within the hemoglobin forming carbaminohemoglobin -This process produces H+
The relationship between CO2 and hemaglobin -CO2 has a higher affinity for Hemoglobin and kicks the hydrogen off which increases the content of H+ in the blood and decreases pH
Chloride Shift -HCO3 diffuses into plasma due to concentration gradient between RBC and plasma -CL ions enter RBC to maintain electroneutrality
CO2 and Metabolism -Metabolic rate determines CO2 production -PaCO2 changes with rate of CO2 production when alveolar ventilation is constant
CO2 Elimination -Ventilation determines rate of CO2 Elimination -Hyperventilation: high rate and/or volume -Hypoventilation: low rate and/or volume
How long does it take pH to adjust in the Respiratory System? 1-3 minutes change in rate and/or volume breathing
Ventilation and Acid-Base Physiology PCO2 = 1/Alveolar ventilation
Hemoglobin -oxygen carrying protein in the RBC -each molecule contains 4 molecules of Fe+ -each Fe+ molecule can reversibly bind to 1 molecule of O2 -Major buffer due to reversible binding with H+ -also binds with CO2
Bohr Effect -Right shift in Curve -Decreased Hb affinity for oxygen -increase H+ -decrease pH -increase CO2 -Increase Temp -Increase 2-3 DPG -O2 becomes more available and is released into tissue cells
Hb in Bohr Effect -more capable of binding H+ to amio acids in Hb -slightly alters structure of Hb -Decreases ability of Hb to carry O2 -Increases blood's ability to carry CO2
Haldene Effect -addition of O2 to the blood enhances CO2 release from Hb -Left Shift in Curve -Increases Hb affinity for oxygen -decrease H+ -Decrease CO2 -Decrease Temp -Decrease 2-3 DPG
Metabolic Acid-Base Physiology -regulated by kidneys -controls excess of H+ or HCO3 through buffers
Kidneys -HCO3- is reabsorbed into the blood -H+ is excreted into urine -total amount of hydrogen ions excreted are significant to metabolic acid-base balance -cannot produce urine with a pH below 4.4
How often does Free H+ urinary acid secretion occur? less than 1% of the time
What accounts for excretion of most nonvolatile acids? phosphate and ammonium urinary buffers
Carbonic anhydrase in Renal Tubular cells -H2CO3 is rapidly dissociated into H+ and HCO3- -HCO3- must react with H+ before it can be reabsorbed as CO2
Renal Correction of Acidosis -excess H+ is excreted in urine -HCO3- binds with Na+ to form NaHCO3 -NaHCO3 is then reabsorbed into the blood
Renal Correction of Alkalosis -excess of HCO3- relative to H+ -HCO3- cannot be reabsorbed without reacting with H+ -Excess HCO3- is excreted in urine
Buffering Systems -prevents drastic changes in pH of a body fluid -converts strong acids and bases into weak acids and bases
Significant deviation from normal pH range -poorly tolerated -May be life threatening
Chemical Equilibrium -Rate of reaction of a substance in one direction is equal to the rate of reaction in the opposite direction
Isohydric Principle -any condition tha causes [H+] to change causes balance of all buffer systems to change at the same time -buffer systems buffer each other -any condition that chanegs balance of any one of the buffer systems also changes balance of all the others
Major Buffering Systems -Hb -Kidneys
Types of Buffer Systems -RBC -HCO3- -Phosphate (HPO4) -Ammonia (NH3-)
RBC Buffering -Carried out by Hb -Hb binds reversibly with H+
HCO3- Bicarb Buffer -found in plasma, RBCs, renal tubules -HCO3- binds with H+ forming H2CO3 -H2CO3 is then converted to CO2 and H20
Phosphate (HPO4) Buffer -renal buffer -sodium phosphate (Na2HPO4) is highly concentrated in tubular fluid -excess H+ takes the place of Na+ to form NaH2PO4) (sodicum acid phosphate) -NaH2PO4 is excreted in urine -Freed Na+ binds with HCO3- and is reabsorbed as NaHCO3
Ammonia (NH3-) Buffer -NH3- is located in tubular fluid -excess H+ binds wtih NH3- and a CL- ion to form NH4CL (ammonia chloride) -NH4CL is excreted in urine -HCO3- binds with Na+ and is reabsorbed
Created by: Mdarrielle09