Correct Answer - Option 1 : Potassium and sodium
Concept:-
- Water constitutes 50 to 70% of the total body weight. Whereas in Newborns it composes from 75 to 80% of their body weight.
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Fluid balance is a method of maintaining the homeostasis in the body via osmoregulation and behavior e.g. concentration of electrolytes.
- If we talk about which electrolytes are found in body fluid, then they contain all of the - sodium, calcium, potassium, chloride, phosphate, and magnesium.
Composition of Body fluids:
- Non-electrolytes: organic molecules
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Electrolytes (most abundant): sodium, potassium, magnesium, and chloride
Regulation of fluid balance in the body is by:
- stimulation of osmoreceptors in the hypothalamus
- release of hormones such as ADH from the posterior pituitary
- increased thirst
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Potassium: is a major water-soluble cation. It is the most abundant intracellular positively charged ion, despite the fact that 90% of potassium is excreted in urine and stool every day.
- The level of potassium in the body is maintained by hormones aldosterone and insulin.
Normal serum K+ level is 3.6 to 5.2 mmol/L
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Sodium: is water-soluble and a major extracellular cation. The normal serum level of sodium is 136-145 mEq/L.
Functions of sodium:
- Maintaining fluid balance in the body
- Nerve impulse transmission
- Stimulating muscle contractions
- Nutrient absorption in the small intestine and their transport through the intestinal cells into the blood.
Reabsorption is renal tubule is regulated by:
- Aldosterone
- angiotensin/renin
- Atrial natriuretic peptide (ANP)
Imbalance in Potassium:
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Hypokalemia: severe potassium depletion can cause cardiac abnormality that includes abnormal cardiac contraction.
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Hyperkalemia: is an increased level of potassium in the blood. It leads to the disruption of electrical impulses that stimulate the heart.
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The antidote to hyperkalemia is Sodium Kayexalate administered either orally or enema.
Sodium imbalances
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Hypernatremia: is when serum sodium level is > 150 mEq/L due to dehydration etc.
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Hyponatremia is when serum sodium level falls below < 135 mEq/L, which can occur due to excessive fluid intake, increased diuretics, diarrhea, etc.