Sodium

what is the chief electrolyte in extracellular fluid?

sodium

normal range for sodium?

135-145 mEq/L

where is sodium mostly found?

extracellular fluid (ECF)

how does sodium affect water movement?

WATER FOLLOWS SODIUM

• sodium loss or gain is accompanied by a loss or gain of water

main jobs of sodium

• regulates extracellular fluid volume and osmolality

• enables muscle contraction

• transmits nerve impulses

• regulates acid base balance

what regulates sodium balance?

• kidneys regulate excretion and reabsorption

• RAAS increases retention via aldosterone

common dietary sources of sodium

• table salt

• processed foods

• restaurant and fast foods

common routes of sodium loss

• GI tract

• kidneys (urine)

• skin (sweat)

recommended adult sodium intake

about 1,500-2,000 mg/day

how do sodium and potassium relate?

often move in opposite directions

• high sodium tends to pair with lower potassium and vice versa

why does sodium matter for neuro and muscles?

sodium shifts change neuron firing and muscle contraction

• imbalances can cause neurological changes and muscle dysfunction

how is sodium transport linked to fluid balance?

moving sodium changes osmolality and pulls water with it