Electrolyte balance

Flashcards covering key concepts related to kidney function, regulation, and the importance of various electrolytes.

What are the three main things kidneys help regulate?

Water balance, electrolyte balance, and acid-base balance.

Why is water balance important?

It determines blood pressure and blood volume.

What is electrolyte balance?

Regulation of ions like sodium, potassium, and chloride between blood and urine.

What does acid-base balance control?

Blood pH by regulating hydrogen ion (H⁺) concentration.

What do osmoreceptors detect?

Blood osmolarity (solute concentration in plasma).

Where are osmoreceptors located?

In the hypothalamus.

What is osmolarity?

The concentration of solutes (salt vs water) in blood.

What happens when osmolarity increases?

Blood has more salt relative to water.

What hormone is produced by the hypothalamus to conserve water?

ADH (antidiuretic hormone).

What does ADH do?

Increases water reabsorption and reduces urine output.

What triggers thirst?

High osmolarity and angiotensin II.

What happens during dehydration?

Water loss → increased osmolarity, decreased blood volume and pressure.

What is the renin-angiotensin system response to low blood pressure?

Activates angiotensin II and increases aldosterone and ADH.

What does aldosterone do?

Increases sodium reabsorption in kidneys (water follows sodium).

What is hyponatremia?

Low sodium in the blood.

What is hyperkalemia?

High potassium levels in the blood.

Why is potassium important?

Controls membrane potential and nerve/muscle excitability.

What is hypokalemia?

Low potassium levels in the blood.

What does chloride do in the body?

Helps form stomach acid (HCl), regulate pH, and balance sodium/water.

What is hyperchloremia?

Too much chloride in the blood.

What usually causes hypochloremia?

Low sodium levels and loss of fluids (chloride follows sodium).