Human Physiology – Urinary System; Fluid and Electrolyte Balance

These flashcards cover key concepts related to the urinary system, fluid and electrolyte balance, and acid-base balance.

What is the concept of balance in fluid and electrolyte homeostasis?

Input + production = utilization + output.

Define positive balance in the context of fluid balance.

Water enters plasma faster than it exits.

What is hypovolemia?

Low blood pressure due to negative water balance.

What is the significance of the medullary osmotic gradient?

It varies in osmolarity, critical for water reabsorption.

What happens to water in the descending limb of the loop of Henle?

Water goes out, leading to reabsorption.

How does ADH affect water reabsorption?

ADH stimulates the insertion of water channels (aquaporins) into the apical membrane.

What occurs when ADH is present?

Urine output decreases and plasma volume increases.

What is Diabetes Insipidus?

A condition characterized by low ADH, leading to decreased plasma volume and increased urine volume.

What triggers the release of renin in the renin-angiotensin-aldosterone system?

Low pressure in the afferent arteriole.

What is the end product of the renin-angiotensin-aldosterone system?

Aldosterone is secreted.

What role does Atrial Natriuretic Peptide (ANP) play?

Decreases sodium reabsorption and increases sodium excretion.

What is hypernatremia?

High plasma sodium levels.

What role does aldosterone play in sodium reabsorption?

It increases the number of Na+/K+ pumps and sodium reabsorption.

What are the functions of parathyroid hormone?

It increases calcium in the blood and activates vitamin D.

What is hypokalemia?

Low plasma potassium levels.

What is metabolic acidosis characterized by?

A pH lower than 7.35.

What is the function of bicarbonate in acid-base balance?

It acts as a buffer to help maintain pH levels.

What does the Henderson-Hasselbalch equation describe?

The relationship between bicarbonate and CO2 in regulating pH.

What is the pH range for metabolic alkalosis?

Higher than 7.45.

What triggers muscle contraction and secretion in the body?

Calcium balance.

What happens during renal compensation of acid-base balance?

Hydrogen ions can be excreted in the urine.

What occurs in respiratory acidosis?

Increasing plasma CO2 levels.

What occurs in respiratory alkalosis?

Decreasing plasma CO2 levels.

What is nephrogenic diabetes insipidus?

A condition caused by a mutation in the gene coding for the ADH receptor.

What is the effect of aldosterone on potassium balance?

It regulates the secretion of potassium.

Describe the importance of the loop of Henle in water reabsorption.

It creates an osmotic gradient necessary for reabsorption of water.

What is calculated using the Henderson-Hasselbalch equation in renal physiology?

The pH based on bicarbonate and CO2 levels.