Physiology of the Kidneys

These flashcards cover the essential physiology and functions of the kidneys as introduced in the lecture notes, focusing on key concepts such as nephron function, hormonal regulation, and renal processes.

What are the primary roles of the kidneys in the body?

Filtration of blood, reabsorption of essential substances, and secretion of wastes.

What is the functional unit of the kidneys?

Nephron.

What percentage of plasma filters out of the glomerulus into the glomerular capsule?

Twenty percent.

What is the role of the afferent arterioles in the kidney?

They bring blood to the glomeruli.

What is reabsorption in the context of kidney function?

Movement of fluid and solutes from the tubules back into the peritubular capillaries.

What triggers the secretion of ADH (antidiuretic hormone)?

Changes in plasma osmolarity.

What is glucosuria?

Excretion of excess glucose in urine due to high plasma glucose concentration.

What is the function of the loop of Henle in nephron?

To create a hypertonic interstitial fluid for water reabsorption.

What happens during acidosis in renal physiology?

Increased secretion of H+ and bicarbonate reabsorption to correct pH.

How do the kidneys control Na+/K+ balance?

Through filtration, reabsorption, and secretion influenced by hormones such as aldosterone.

What occurs in the proximal convoluted tubule?

Reabsorption of glucose, amino acids, and salt; secretion of wastes.

What is renal plasma clearance?

Volume of plasma cleared of a substance by kidneys per unit time.

How does the body respond to overhydration?

Decreased secretion of ADH, resulting in more dilute urine.

What is the countercurrent multiplier system?

Mechanism in the nephron that helps create a high osmotic gradient in the renal medulla.

What role do osmoreceptors in the hypothalamus play?

They sense changes in plasma osmolarity and regulate ADH secretion.

What is the significance of nephron loop (of Henle)?

It allows for the reabsorption of water and salts, contributing to urine concentration.

What effect does aldosterone have on kidney function?

Stimulates Na+ reabsorption and K+ secretion in the distal nephron.

What occurs to urine composition during alkalosis?

Decreased bicarbonate reabsorption to compensate for high pH.

What is filtration in regards to kidney function?

Movement of fluid and solutes from the glomerulus into the glomerular capsule.

What happens in the collecting duct of the nephron?

Final adjustments in water reabsorption and concentration of urine.