WATER AND ELECTROLYTE BALANCE. 2

Question 1

What are electrolytes, and why are they essential?

Answer 1

Electrolytes are essential components involved in numerous processes, including volume and osmotic regulation, myocardial rhythm and contractility, and cofactors in enzyme activation. They play critical roles in maintaining proper bodily functions.

Question 2

Name three electrolytes and describe one process each that they are involved in.

Answer 2

1. Sodium (Na+): Involved in muscle contraction.
2. Potassium (K+): Important for myocardial rhythm and contractility.
3. Chloride (Cl-): Helps maintain osmotic pressure.

Question 3

How do Magnesium (Mg2+) and Calcium (Ca2+) contribute to myocardial rhythm and contractility

Answer 3

Magnesium and Calcium are crucial for cardiac excitability and muscular contraction processes, ensuring proper heart function.

Question 4

What role does Zinc (Zn2+) play according to the text?

Answer 4

Zinc regulates adenosine triphosphate enzymes, which are essential for energy production and cellular processes.

Question 5

Specimens for electrolyte determination

Answer 5

• serum, plasma
• No preservatives are needed for urine for sodium, chloride and potassium ions
• Body fluid aspirates, feces
• GI fluid samples

Question 6

Roles of sodium ions

Answer 6

• responsible for almost one half of the osmotic strength of plasma
• Takes part in maintaining normal water distribution and osmotic pressure in the ECF

Question 7

Sodium {Na+}

Answer 7

• major cation of the extracellular fluid
• 1 to 2 mmol/d and the excess is excreted by kidneys

Question 8

Specimens for sodium determination

Answer 8

• serum, plasma and urine maybe stored at 4 degrees
• Lipemic samples should be ultracentrifuged and the inflanatant

Question 9

Determination of sodium

Answer 9

Can be determined by:
1. Atomic absorption spectrophometry
2. Flame emission spectrophometry
3. Electrochemically with an Na+-ISE

• ISE ARE THE COMMONEST METHODS USED

Question 10

Clinical significance of sodium or implications that result due to low levels of sodium

Answer 10

1. Hyponatremia manifests as nausea, generalized weakness and mental confusion

Question 11

Categories of hyponatremia

Answer 11

1. Hypo-osmotic
2. Hyper-osmotic
3. Iso-osmotic

Question 12

How does hypo-osmotic hyponatremia start

Answer 12

• due to depletion and dilutional hyponatremia

Question 13

What clinical implications are associated with hypo-osmotic hyponatremia

Answer 13

1. Advanced renal failure
2. Congestive heart failure
3. Hepatic cirrhosis
4. Nephrotic syndrome

Question 14

Clinical implications associated with hypo-osmotic hyponatremia

Answer 14

1. Severe hyperglycemia

Question 15

Clinical implications associated with iso-osmotic hyponatremia

Answer 15

• most likely explains pseudohyponatremis

Question 16

Other categories of hyponatremia and their causes

Answer 16

1. Hypovolemic hyponatremia is caused by dehydration
2. Hypervolemic hyponatremia is caused by the receiving of hypertonic saline or sodium bicarbonate
3. Normovolemic hyponatremia maybe be observed in diabetes insipidus