Urinary System - Chapter 25

These flashcards cover key concepts and details about the urinary system and kidney functions from Chapter 25.

What are the main functions of the kidneys?

The kidneys regulate water volume, solute concentration, ion concentrations, long-term acid-base balance, excrete wastes, produce erythropoietin, activate vitamin D, and perform gluconeogenesis.

What is the role of nephrons in the urinary system?

Nephrons are the structural and functional units of kidneys that form urine.

What are the two components of the renal corpuscle?

The two components are the glomerulus and the glomerular capsule (Bowman's capsule).

What is the function of the glomerulus?

The glomerulus is a tuft of capillaries that allows for efficient filtrate formation due to its high permeability.

What are the three major parts of the renal tubule?

The proximal convoluted tubule, nephron loop, and distal convoluted tubule.

What is the primary role of principal cells in the collecting ducts?

Principal cells maintain water and sodium balance.

What are the two major classes of nephrons?

Cortical nephrons and juxtamedullary nephrons.

What is glomerular filtration rate (GFR)?

GFR is the volume of filtrate formed per minute by both kidneys, typically around 120-125 ml/min.

What are the three processes involved in urine formation?

Glomerular filtration, tubular reabsorption, and tubular secretion.

What is the role of aldosterone in the kidneys?

Aldosterone promotes Na+ reabsorption and influences water retention, which increases blood pressure.

How does the countercurrent mechanism help in urine concentration?

It establishes and maintains a medullary osmotic gradient that allows the kidneys to concentrate urine based on hydration levels.

What is the significance of renal clearance tests?

Renal clearance tests help to determine the GFR and assess renal function.

What is the typical composition of urine?

Urine is composed of about 95% water and includes nitrogenous wastes and various solutes.

What are diuretics?

Diuretics are chemicals that enhance urinary output, affecting water reabsorption.

What role do ureters play in the urinary system?

Ureters convey urine from the kidneys to the bladder.

What are the layers of the urinary bladder wall?

The layers include the mucosa, muscular layer (detrusor muscle), and fibrous adventitia.

What stimulates micturition?

Micturition is stimulated by the contraction of the detrusor muscle and the relaxation of the internal and external urethral sphincters.

What is the anatomical difference between the male and female urethra?

The female urethra is shorter (3-4 cm) and closely bound to the anterior vaginal wall, while the male urethra is longer (15 cm) and serves a dual function for both urine and semen.