Karteikarten
BMS11-1038 Kidney Function IV: Regulation of Acid Base status
Karten in diesem Stapel (25)
- 1Where are the three locations of renal acid/base handling?1. Proximal convoluted tubule
2. Ascending loop of henle
3. Cortical collecting ducts at intercalated cell type A - 2When does H+ excretion occur?When there is no bicarbonate in the tubular lumen, H+ will combine with a non-bicarbonate buffer and be excreted
- 3What is the pH determining acidosis/alkalosis?7.35
- 4What is the bicarbonate buffer system?CO2+H20<->H2CO3<->HCO3-+H+
- 5What is respiratory acidosis caused by?Insufficient CO2 excretion by lungs aka hypoventilation
- 6What is metabolic acidosis caused by?Fall in plasma HCO3- due to:
1. True HCO3- deficet (renal tubular acidosis/diarrhea)
2. H+ gain from exogenous acid, abnormal carb/lipid/protein metabolism - 7What causes respiratory alkalosis?Fall in pCO2 due to:
1. Excess central respiratory drive (from aspirin overdose/fever)
2. Hypoxic stimulation (altitude increase, hyperventilation, pulmnary embolism) - 8What causes metabolic alkalosis? pH>7.45Increased plasma bicarbonate due to:
1. Loss of gastric acid from vomiting
2. Excess aldosterone (increases H+ ATPase)
3. Excess alkali ingestion - 9What causes acute respiratory acidosis?1. Airway obstruction eg. asthma
2. Drug induced eg. narcotics - 10What are the three sources of acid loss?1. Utilisation of H+ to metabolise organic anions
2. Vomit/urine
3. Hyperventilation - 11What are the 3 sources of acid gain?1. Metabolic acid production from proteins etc.
2. H+ intake from CO2
3. Loss of bicarbonate in urine/diarrhea - 12What 3 types of airway obstriction cause CHRONIC respiratory acidosis?1. Lung damage (fibrosis)
2. Chest wall disorders
3. Neuromuscular disorders like lateral scelerosis - 13pH= pK+ log[(...)/(...) CB WA1. HCO3- (CB)
2. H2CO3 OR PCO2 - 14Normal Values Body pH= ... Parterial CO2: ... Aterial/venous [HCO3-]= ... Aterial pH= ...1. pH=7.35-7.45
2. Parterial CO2=4-6kPa
3. 25nM
4. arterial pH=7.5 - 15How does the respiratory brain stem respond to metabolic acidosis?Increase ventilation to decrease pCO2, increasing pH
- 16How does glutamine metabolism add new HCO3 to the plasma?1. Glutamine (filtered) enters tubular epithelial cell
2. Glutamine breaks down into NH4+ + HCO3-
3. HCO3- reabsorbed into interstitial fluid
4. NH4+ goes to tubular lumen via Na+NH4+ cotransporter and is excreted - 17How does filtered HCO3 in the filtrate get reabsorbed?1. In the tubular lumen, it combines with H+ to form H2CO3
2. H2CO3--> CO2+H20, enters tubule epithelial cell
3. Reabsorbed (see next slide) - 18How does bicarbonate reabsorption occur in the tubular epithelial cell?1. H20+CO3 combines into H2CO3 via enzyme carbonic anhydrase
2. H2CO3-->H+ + HCO3-
3. HCO3- reabsorbed via HCO3/Na+ cotransporter
4. H+ goes to tubular lumen via H+/Na+ exchanger - 19How do the following respond to respiratory alkalosis? 1. Chemical buffers 2. Respiratory brain stem 3. Renal mechanisms1. As CO2 concentration falls, plasma HCO3 combines with H+ to form H20+CO2. So, concentration of HCO3-/H+ drops
2. Lower ventilation if possible
3. Lower H+ secretion in tubules, so less to combine with HCO3- for reabsorption (so less HCO3- in plasma). Produces alkaline urine - 20How do the following respond to respiratory acidosis: 1. Chemical buffers 2. Brainstem respiratory centre 3. Renal mechanisms1. As more CO2 is present, more HCO3- + H+ is produced via bicarbonate buffer system
2. Cannot be adjusted as ventilation is issue
3. Increase HCO3- reabsorption to increase secretion/excretion of H+
Increase glutamine metabolism to increase HCO3 in plasma
Produces acidic urine - 21How do the following respond to metabolic alkalosis: 1. Chemical buffers 2. Respiratory brainstem 3. Renal mechanisms1. Fall in H+ pushes rxn left, generating more HCO3- and H+, and decreasing CO2
2. Respiration slows (hypoventilation) to retain more CO2 to make HCO3-/H+
3. Excess bicarbonate excreted - 22How do renal mechanisms respond to metabolic acidosis?1. Increase H+ secretion
2. Increase glutamine metabolism
Both these raise plasma HCO3 to a normal level - 23How do chemical buffers respond to metabolic acidosis?1. Rise in H+ will cause HCO3- to drop as it combines to form CO2. pCO2 will rise
- 24Chemical buffers work in {{c1::seconds}} eg. ... in ECF,...in ICF, ...in urine Brain respiratory center works in {{c5::minutes}} in response to changes in arterial changes Works by...to expel/retain CO2 Renal mechanisms work in ... For each H+ secreted, HCO3- is added to blood1. Seconds
2. Bicarbonate, phosphate, phosphate/ammonia
1. Minutes
2. pCO2/pO2
3. Adjusting ventilation
1. Hours to days - 25—
Informationen
- Beschreibung
- BMS11 - Renal System Karteikarten am BMS11-1038 Kidney Function IV: Regulation of Acid Base status, erstellt von Evian Chai am 28/04/2020.
- Erstellt von
- Evian Chai
- Aufrufe
- 17
- Tags
- Bewertung