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15 Cards in this Set
- Front
- Back
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Normal K+ __ meq/l
Function of K: Role in ____ and ____ synthesis, maintains resting membrane potential in muscle cells and neurons via NaKATPase, determiens excitablilty, allows ___ _____ to be generated |
4-5meq/l
protein glycogen action potentials |
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Low and High K Symptoms:
Inability to generate AP in muscles: cramps, weakness/paralysis - starts in ____ ____ changes |
legs
EKG (PACs, PVCs, bradycardia, atrial or junctional tachy, AV block, v-tach/fib) |
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EKG changes:
Hypokalemia has _____ T waves and what unique wave? Hyperkalemia has ____ T waves Both have PR interval _____ and widened ___ interval |
depressed
U wave after T wave elevated prolongation QRS |
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Which electrolyte increases threshold potential and protects against hyperkalemia?
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Hypercalcemia
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Metabolic acidosis does what to potassium?
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Causes K+ to be released from cells as HCl is buffered into cells which exacerbates hyperkalemia
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Insulin and catecholamines move K __ the cells by increasing activity of Na/K/ATPase
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into
uptake of K into skeletal muscle and liver |
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Acidemia: K moves ___ of cells as H is buffered ___ cells
Alkalosis: K moves ___ cells as H_ is buffered where? |
out
into into into the extracellular fluid |
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What is the major route of elimination of Potassium?
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Kidneys - some K lost in stool or sweat, but not clinically important
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_____ causes K secretion by principal cells of collecting tubule
Secretion also determined by plasma K conc and urine flow in _____ tubule |
Aldosterone
distal |
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K is reabsorbed at what two points?
In severe hypokalemia, K can be reabsorbed in collecting duct by what cells? |
proximal tubule - following water and Na
thick ascending loop of henle via NaK2Cl carrier in luminal membrane intercalated cells |
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Where is K secreted and by what type of cells?
What signals the secretion of K? |
Distal tubule and collecting tubule
Secreted by principal cells Aldosterone |
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Hypokalemia causes:
Decreased intake (rare) Increased entry into cells Increased __/____/____ losses Dialysis |
GI, urinary, sweat
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You can become hypokalemic by increased entry of K into cells. What causes this?
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Metabolic alkalosis
Hyperinsulinemia Increased catecholamines/beta agonists |
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____ urinary K indicates GI losses
Acidosis: ___ GI losses such as ____ Alkalosis: ____ GI losses such as ______ |
low
lower - laxatives, villous adenoma upper - vomiting |
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____ urinary K (therefore kidney losses)
Acidosis: Ketoacidosis Alkalosis: Normotensive - vomiting, diuretics, Bartter's Hypertensive - High renin - diuretics Hypertensive Low renin - measure _____ |
High
aldosterone if it's low, exogenous mineralcorticoid if it's high, adrenal adenoma or hyperplasia |
