Why does the renal system produce ammonia? How does it work? How does it affect acid-base balance?
Ammonia excreted in the urine promotes acid excretion; ammonia returned to the systemic circulation is metabolized in the liver in a HCO3(-)-consuming process,
Ammonia production and transport are regulated by a variety of factors, including extracellular pH and K(+)
pH> pKa.Pronated or deprotated
Deprotanated
Aldosterone
Increases Na+ retention Decreases K+ retention
Chief Intracellular Ions
K+, HPO4-, Protein, Mg 2+
What causes the production of fixed acids?
The incomplete metabolism of carbohydrates, fats, and proteins
Henderson-Hasselbalch equation
pH= pKa + log (A-/HA)
Fixed acids
n acid produced in the body from sources other than carbon dioxide, and is not excreted by the lungs.
Examples of types of nutients that lead to production fixed acids or excess base
Wine, certain fruits
Ions in Cellular gradients
K+, Na+, Cl-, and Ca 2+
The stronger the acid the _______ the pKa.
Lower
Relationship between Ka and pH
High pH= low Ka, Low pH= high Ka
Normal blood pH range
7.35-7.45
Is the respiratory system an open or closed system?
Open
What is normal gap value?
12-14
Causes of acidosis with an unchanged gap acidosis
HCl or Nh4Cl ingestion
Diarrhea
Inhibition of renal carbonic anhydrase
Renal tubular acidosis
Defects of diabetes insipidus
Failure to respond to ADH
Glutaminase breaks down ____
Glutamine; into Glutamate and NH3
Equivelancy point
when the moles of a standard solution (titrant) equal the moles of a solution of unknown concentration
Relationship between pH and pKa at midpoint
pH=pKa
Normal HCO3- range
22-26
ADH
Increases water rentention
Diamox is prescribed in response to acidosis or alkalosis
Alkalosis; increases release of bicarbonate in urine
Are Na+ and H+ concentrations inveresly or directly related?
Inversely
Is the pCo2 in the lungs low or high?
Low
The total osmalirity of the plasma is dependent mainly on ___, ___, and __.
Na+, Cl-, and HCO3-
Relationship between ammonia and K+ production
Increase in Ammonia= Decrease in Potassium
Midpoint ratio
1:1
Anion gap equation
Anion gap= Na+ - (HCO3-+ Cl-)
Strong acid
any acid that ionizes completely in solutions
What is an ampholyte?
molecules that contain both acidic and basic groups and will exist mostly as zwitterions in a certain range of pH.
Normal pCO2 range
35-45
Renal tubular acidosis II
Decrease in the recovery of HCO3-
Bicarbonate buffer system
pH< pKa. Protanated or deprotonated
Protonated
Weak acid
an acid that dissociates incompletely, releasing only some of its hydrogen atoms into the solution.
Where is carbonic anhydrase located?
RBC
Possible causes of high gap acidosis
Renal failure
Ketoacidosis
Lactic acidosis
Methanol ingestion
Renal tubular acidosis I
Increase in NH3 excretion
Resists change in pH with the addition of H+ or OH-
Buffer
What is the difference between chief intracellular ions and ions in interstitial fluids?
Interstitial fluid has less protein
Gastric Juice pH
1.5-3.0
Pancreatic Juice pH
7.8-8.0
Urine pH
4.6-8.2
Hydrogen-bonding activity requires a maximum of _________ hydrogen bonds with neighboring molecules
4
Plasma Osmotic activity
0.308 M sucrose and 0.154 M NaCl or 0.9% isotonic saline.
Blood plasma and isotonic saline
286 mOsmolar solution
·High blood ketoacids and hyperglycemia can lead to _______ loss or dehydration that accompainies __________ and __________
Water; ketouria; glucosuria
Carbonic Anhydrase contains what metal?
Zn
Major sites of carbonic anhydrase are ________ and __________.
RBC and renal tubular epithelium
Where in the kidneys does NH3 and H+ enter?
Distal convoluted tubule
Where in the kidneys is HCO3- recovered?
Proximal convulted tubules
For every bicarbonate recovered, you need a _________.
Proton
How is the Na+ gradient established?
Na+- K+ pump
Total Urine Acidity
Titratable + NH4+ + HCO3-
Fixed acids must be excreted through the __________
Renal system
Increased acetoacetic acid can result in _____
Diabetes meliitus
Substances that if ingested can cause acidosis
Salicylates
methanol
Any toxin depressing cardio- respiratory activity
Substances that if ingested can cause alkalosis
NaHCO3
Salicylate
Acidosis in the GI/Kidneys are caused by:::
Retention of fixed acid (Renal Failure)
Inability to release urinary NH3
Loss of HCO3- (Diarrhea or carbonic
anhydrase inhibitor)
Proximal renal tubular acidosis (RTA)
Are GI/Kidney disorders metabolic or respiratory?
Metabolic
Alkalosis in GI/ Kidney can result from:
Loss of H+ via vomiting
Metabolic acidosis disorders
Diabetic ketoacidosis
Lactic acidosis from hypoxia-
Starvation ketosis
Metabolic alkalosis disorders
Dissolution of bone (hyperparathyroid disease)
Respiratory acidosis
Brain stem injury
Airway obstruction
Pulmonary disorders
Drug overdose
Emphysema
Chronic Bronchitis,
Severe Asthma
Respiratory alkalosis
Anxiety
Head injury,
High altitude,
Iatrogenic hyperventilation