Chapter 24, Lesson 2: Electrolyte Balance

Flashcards from Chapter 24, Lesson 2 of McGraw Hill Anatomy and Physiology, Tenth Edition, by Kenneth S. Saladin.

Electrolyte balance

The amount of electrolytes absorbed by the small intestine balances the amount lost in urine

Electrolyte functions

• Metabolic reactions

• Membrane electrical potential regulation

• Osmolarity adjustment

• Water content regulation

Sodium

The principal cation in the ECF that signals nerve and muscle cells while regulating hydration

0.5 grams

The amount of sodium an adult needs per day

3 to 7 grams

The typical sodium intake of an American adult; caused by excessive preservatives

Aldosterone

Hormone that plays the primary role in adjusting sodium excretion

Antidiuretic hormone (ADH)

Hormone that modifies water excretion independently of sodium excretion; higher sodium levels lead to more retention

Hypernatremia

High sodium levels greater than 145 mEq/L; can result in water retention, hypertension, and edema

Hyponatremia

Low sodium levels lower than 130 mEq/L; can be caused by excess body water and is followed by rapid excretion through sweat or urine

Potassium

The principal cation in the ICF that signals nerve and muscle cells; linked to sodium homeostasis but with dangerous imbalance effects

Hyperkalemia

High potassium levels above 5.5 mEq/L; can lead to overexcitation and cardiac arrest

Hypokalemia

Low potassium levels under 3.5 mEq/L; can be caused by excessive fluid loss and leads to underexcitation and weakened muscles (including the heart)

Calcium

Electrolyte that functions in skeleton strength, muscle contraction, neurotransmission, and blood clotting

Hypercalcemia

High calcium levels over 5.8 mEq/L that inhibits depolarization of nerve and muscle cells; can cause weakness, depressed reflexes, cardiac arrythmias

Hypocalcemia

Low calcium levels under 4.5 mEq/L that increases excitability; can lead to tetany, laryngospasm, death

Magnesium

Electrolyte that aids in ATP and intestinal absorption

Hypermagnesemia

High magnesium levels

Hypomagnesemia

Low magnesium levels

Chloride

The most abundant anion in the ECF required for stomach acid formation and body pH regulation

Hypochloremia

Low chloride levels that can result from hyponatremia, hyperkalemia, or acidosis

Hyperchloremia

High chloride levels that can result from dietary excess