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REGULATION OF HYDROGEN ION
CONCENTRATION IN HUMAN BODY
INTRODUCTIONHOMEASTASIS
FLUID CONTENT
EXTRA CELLULAR FLUID
INTRA CELLULAR FLUID
WATER IN THE BODY
ACIDS AND BASESWHAT ARE ACIDS
WHAT ARE BASES
RECAP OF CONCEPTS
HYDROGEN ION IN BODY
pH
CONTROL SYSTEMS
CONTROL SYSTEMSBUFFER PAIRS
BICARBONATE BUFFER PAIR
EG:ADDITION OF ACIDS AND BASES
HAEMOGLOBIN BUFFER
LACTATE BUFFER
PHOSPHATE BUFFER PAIR
PROTEIN BUFFER PAIR
PHYSIOLOGICAL CONTROL SYSTEM
RESPIRATORY CONTROL SYSTEM
HYPERCAPNIA
HYPOCAPNIA
HYPERVENTILATION
HYPOVENTILATION
RENAL CONTROL SYSTEMREABSORPTION OF BICARBONATE ION
RETENTION OF BICARBONATE ION
Introduction
60% of male body is water
50% of female body is water
2/3 of the body is ICF
1/3 of the body is ECF
INPUT: water in food, ingested liquid
OUTPUT: water vapor, sweat, urine, feces
Acids Proton donors
Acidity reflects on free hydrogen ions
Strong acids dissociate completely, liberate all H+ ions
Weak acids dissociate partially
Bases
Bases are proton acceptors
Strong bases dissociate quickly and tie up H+ ions almost immediately.
Weak bases slowly accept protons.
What is pH?The amount of hydrogen ions present in the
solution.
1- 14 ranges the pH scale. 7 is neutral. Below 7 is acidic. Above 7 is basic.
pH of arterial blood when above 7.45 causes alkalosis.
pH below 3.5 causes acidosis.
Continued…Acids and bases continually enter and exit body.
H+ ions enter through
Carbonic acid and lactic acid – via aerobic and anaerobic respiration
Sulphuric acid-S+ containing amino acid oxidation
Phosphoric acid- phosphoproteins and ribonucleotides break down
Acidic ketone bodies- including acetone, acetoacetic acid and beta-hydroxybutyric acid thru’ incomplete breakdown of fats
Minerals after metabolises may be acid forming or basic forming minerals.
Acid forming minerals- chlorine, sulphur, phosphorus (present in meat, fish, poultry, eggs, wheat, corn, oats)
Base forming minerals- potassium, calcium, sodium, magnesium (present in dry fruits and vegetables)
Rhubarb (oxalic acid),cranberries (benzoic acid)- direct acid forming food
Antacids- sodium bicarbonate and calcium bicarbonate – direct base forming materials
HomeostasisCarbonic anhydrase enzyme.
Control systems
Chemical Control Sytem
Bicarbonate Buffer PairsECF buffer
When strong acid is added pH is lowered.
Hence this buffer pair forces the addition of strong base that neutralizes this effect.
Chloride shift
Bicarbonate loading.
RATIO OF ACID:BASE=20:1
Increase is uncompensated acidosis (uncompensated alkalosis.
Phosphate Buffer PairSodium salts of dihydrogen phosphate and
monohydrogen phosphate.
H+ released by strong acid is tied up by weak acids
Strong bases are converted in to weak bases.
Buffer of ICF and urine.
Protein Buffer PairAmino acids have exposed groups that act as
bases and accept H+
A single protein molecule may be acidic or basic depending on pH.
They are amphoteric in nature.
Hb is an intracellular buffer.
Respiratory Control
Carbon dioxide is expelled from lungs, during its unloading the balance is shifted and hydrogen ions are liberated from carbonic acid and reincorporated into water.
Due to protein buffer hydrogen ion is not accumulated and dos not affect blood pH.
Hypoventilation causes acidosis
Hyperventilation causes alkalosis
Renal Control System
Presentation by Florence Suganya R
12/PZO/004