Electrolytes and Acid Base Flashcards
How much of an adults body weight is made up from Intracellular fluid?
40%
How much of an adults body weight is made up of extracellular fluid?
20%
What is extracellular fluid made up from?
Interstitial fluid and plasma
What is the primary reason for an electrolyte imbalance?
Diet
What is the definition of osmolality?
The distribution of solutes
What is the sodium potassium pump?
3 sodiums out of the cell for every 2 potassiums pumped into the cell
What does ADH do?
Secretion of ADH Causes resorption of water into the thick loop of henle
When may ADH be secreted?
When there is hyperosmolality (blood has a high concentration of salt, glucose and other substances)
What is the link between flow rate, Aldosterone and Potassium
High flow rate promotes potassium excretion
Low flow rate inhibits excretion
What is one of the affects of hypocholeraemia?
Low levels of chloride means it cannot help co-transport sodium
therefore potassium may also need to be excreted to help with the balance
Why does organic acidosis (ketones, lactate…) not promote kyperkalaemia?
They travel with H+ ions that move in and out of cells instead of Potassium
How may we measure electrolytes?
Using an Ion-Selective Electrode
Why may platelets clotting impact the results of electrolytes?
When platelets clot they release potassium so thrombocytosis may result in a higher serum K+
What can cause a sodium excess?
- Salt poisoning
- Administeration of hypertonic saline
- Decreased renal excretion
What causes normatraemia when the animal is dehydrated?
- Net loss of isotonic fluids
- Net retention of isotonic fluids
What causes hyponatraemia?
- Sodium loss is larger than the water loss
- Shift of water from the ICF to the ECF
What can cause hyperkalaemia?
- Shifting of K+ from the ICF to the ECF
- Increased total K+ due to decreased renal excretion
What are electrolytes?
Any substance that ionises when dissolved in water
e.g sodium, potassium, chloride
How is sodium regulated?
- Activation of the RAS system -> Angiotensin II -> Resorption of Na+, Cl-, and H2O in the collecting tubules
What effect does ANP have on sodium?
Sodium resorption in the distal nephron
What occurs when we have hyperosmality?
ADH is released, there is then increased resportion of H2O
What is the effect of inorganic acidosis on potassium?
may cause potassium to shift out of cells (hyperkalaemia in peripheral blood)
What is the effect of inorganic acidosis eg lactate or ketoacidosis on Potassium?
- Typically does not cause hyperkalaemia in peripheral blood
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What can metabolic alkalosis cause in terms of potassium?
Mild hypokalaemia
