Renal Quiz 3: Sodium Balance Lectures

A set of flashcards reviewing key concepts from the lecture on sodium balance, focusing on sodium regulation, kidney function, hormonal influences, and clinical implications.

What regulates sodium content in the body, despite high sodium intake?

The kidneys regulate sodium content.

What is the term for increased sodium excretion?

Natriuresis.

What happens in negative sodium balance?

More sodium is lost than taken in, leading to sodium depletion and decreased extracellular fluid volume.

What hormone predominantly controls sodium reabsorption in the distal nephron and collecting duct?

Aldosterone.

What two factors contribute to the disruption of sodium balance in certain pathological states?

Sodium wasting occurs in adrenal deficiency, and excess sodium retention occurs in advanced kidney disease.

How much sodium is typically required per day to maintain sodium balance?

About 10,000 milliequivalents.

What percentage of filtered sodium is typically reabsorbed in the proximal tubule?

Approximately 65%.

What causes pulmonary edema in sodium retention?

Sodium accumulation leads to fluid volume expansion.

What is the primary mechanism by which the kidneys excrete sodium?

By filtering sodium from plasma, reabsorbing the needed amount, and excreting the surplus.

How does increased arterial blood pressure affect sodium excretion?

It causes a rapid increase in sodium excretion via pressure natriuresis.

What is the condition where sodium balance is disrupted leading to organ failure?

Negative sodium balance.

What is a common result of excessive sodium intake in contrast to the body's needs?

Excessive sodium can lead to hypertension.

What is the main impact of atrial natriuretic peptide (ANP)?

It promotes sodium excretion and reduces blood volume.

How does the body typically maintain constant extracellular fluid volume?

By matching sodium intake with its excretion.

What is a significant consequence of kidney failure in terms of sodium balance?

Life-threatening derangements in extracellular fluid and plasma volume.

What is the average sodium excretion percentage from filtered sodium?

About 0.5%.

What happens when sodium reabsorption is inhibited in the proximal tubule?

Both sodium and water reabsorption are decreased, leading to increased sodium excretion.

What is one physiological state where sodium retention is required?

During pregnancy.

What characterizes salt-sensitive hypertension?

Blood pressure increases with high dietary salt intake and decreases when intake is low.

What is the principal sodium transporter in the collecting duct?

Epithelial sodium channel (ENaC).

How do diuretics affect sodium handling in the kidneys?

They inhibit sodium reabsorption leading to increased sodium excretion.

What does the term 'glomerular tubular balance' refer to?

The intrinsic regulation of sodium reabsorption in the proximal tubule in response to changes in sodium filtration.

What is the main influence of angiotensin II on sodium balance?

It stimulates sodium reabsorption in the kidneys.