Unit 4 Electrolytes

Question 1

What are electrolytes?

Answer 1

Ions capable of carrying an electrical charge.

Question 2

What are the two classifications of electrolytes?

Answer 2

Cations (positively charged) and Anions (negatively charged).

Question 3

What is the major extracellular cation?

Answer 3

Sodium (Na+).

Question 4

What is the major intracellular cation?

Answer 4

Potassium (K+).

Question 5

What is the major extracellular anion?

Answer 5

Chloride (Cl-).

Question 6

What are the major intracellular electrolytes?

Answer 6

Potassium (K+), Magnesium (Mg2+), and Phosphate (PO4-).

Question 7

What is the function of sodium in the body?

Answer 7

Determines plasma osmolality and maintains fluid balance.

Question 8

What pump maintains the sodium concentration in extracellular fluid?

Answer 8

Na-K ATPase pump.

Question 9

Where is most sodium reabsorbed in the kidneys?

Answer 9

Proximal tubules (80%).

Question 10

Which hormone directly increases sodium reabsorption?

Answer 10

Aldosterone.

Question 11

What is the most common method for sodium determination?

Answer 11

Ion Selective Electrode (ISE).

Question 12

What is the normal reference range for sodium in serum/plasma?

Answer 12

135-145 mmol/L.

Question 13

What is hypernatremia?

Answer 13

Increased plasma sodium (>145 mmol/L).

Question 14

What is a major cause of hypernatremia?

Answer 14

Excess water loss, decreased water intake, or increased sodium retention.

Question 15

What is the mortality rate for sodium levels above 160 mmol/L?

Answer 15

60-75%.

Question 16

What is hyponatremia?

Answer 16

Plasma sodium concentration <135 mmol/L.

Question 17

What sodium level is considered a medical emergency?

Answer 17

<120 mmol/L for more than 48 hours.

Question 18

What are major causes of hyponatremia?

Answer 18

Increased sodium loss, increased water retention, or water imbalance.

Question 19

What is the major intracellular cation?

Answer 19

Potassium (K+).

Question 20

What percentage of potassium is found in plasma?

Answer 20

Only 2%.

Question 21

Which organ regulates potassium levels?

Answer 21

Kidneys.

Question 22

Which hormone promotes potassium excretion?

Answer 22

Aldosterone.

Question 23

What is the normal reference range for potassium in serum?

Answer 23

3.5-5.1 mmol/L.

Question 24

What is hyperkalemia?

Answer 24

Plasma potassium >5.1 mmol/L.

Question 25

What are causes of hyperkalemia?

Answer 25

Renal failure, acidosis, muscle injury, hemolysis, excess potassium intake.

Question 26

What is hypokalemia?

Answer 26

Plasma potassium <3.0 mmol/L.

Question 27

What is a common cause of hypokalemia?

Answer 27

Diuretic use, Cushing’s syndrome, insulin overdose.

Question 28

What is the most common method for potassium determination?

Answer 28

Ion Selective Electrode (ISE) using valinomycin.

Question 29

What is the most abundant cation in the body?

Answer 29

Calcium (Ca2+).

Question 30

What is the function of calcium?

Answer 30

Bone mineralization, muscle contraction, cardiac function, blood coagulation.

Question 31

Which hormones regulate calcium levels?

Answer 31

Parathyroid Hormone (PTH), Vitamin D, and Calcitonin.

Question 32

What is the normal total calcium range in adults?

Answer 32

2.15-2.50 mmol/L (8.6-10.0 mg/dL).

Question 33

What is the main cause of hypercalcemia?

Answer 33

Primary hyperparathyroidism, malignancy, vitamin D toxicity.

Question 34

What is the main cause of hypocalcemia?

Answer 34

Hypoparathyroidism, vitamin D deficiency, renal disease.

Question 35

Which is the fourth most abundant cation in the body?

Answer 35

Magnesium (Mg2+).

Question 36

What is the function of magnesium?

Answer 36

Cofactor in enzyme activation, DNA replication, muscle function.

Question 37

What is the primary storage site of magnesium?

Answer 37

Bones (53% of total body magnesium).

Question 38

What is the reference range for magnesium in serum?

Answer 38

0.63-1.0 mmol/L.

Question 39

What is hypermagnesemia?

Answer 39

Excess magnesium (>1.0 mmol/L) due to renal failure or increased intake.

Question 40

What is hypomagnesemia?

Answer 40

Low magnesium (<0.63 mmol/L) due to malabsorption, alcoholism, diuretics.

Question 41

What is the major extracellular anion?

Answer 41

Chloride (Cl-).

Question 42

What is the function of chloride?

Answer 42

Maintains osmotic pressure and acid-base balance.

Question 43

What is the normal reference range for chloride in plasma?

Answer 43

98-107 mmol/L.

Question 44

What is hyperchloremia?

Answer 44

Excess chloride due to dehydration, kidney disease, or excessive base loss.

Question 45

What is hypochloremia?

Answer 45

Low chloride due to heart failure, Addison’s disease, or prolonged vomiting.

Question 46

What is the predominant intracellular anion?

Answer 46

Phosphate (PO4-).

Question 47

What is the function of phosphate?

Answer 47

Component of ATP, DNA, and cell membranes.

Question 48

What hormone regulates phosphate levels?

Answer 48

Parathyroid Hormone (PTH).

Question 49

What is the normal reference range for phosphate in adults?

Answer 49

0.78-1.42 mmol/L (2.4-4.4 mg/dL).

Question 50

What is hyperphosphatemia?

Answer 50

Increased phosphate due to kidney failure or hypoparathyroidism.

Question 51

What is hypophosphatemia?

Answer 51

Low phosphate due to hyperparathyroidism, chronic diarrhea, diuretics.