Genitourinary Disorders Flashcards

Flashcards covering genitourinary anatomy, physiology of urine formation, hormonal regulation, urinalysis parameters, and various urinary and renal disorders including failure and dialysis.

What is the structural unit of the kidney?

The lobe, which consists of a medullary pyramid and the overlying cortex.

Identify the three main processes in the formation of urine.

1. Filtration, 2. Reabsorption, 3. Secretion.

What occurs during filtration in the renal corpuscles?

A large volume of fluid, wastes, nutrients, and electrolytes passes from glomerular capillaries into the Bowman capsule, while cells and protein remain in the blood.

What is the primary function of the proximal convoluted tubules (PCT) in reabsorption?

The PCT is responsible for the reabsorption of most water, all glucose and amino acids, and nutrients/electrolytes to maintain homeostasis.

Which hormone is secreted by the posterior pituitary and facilitates water reabsorption in the distal convoluted tubules and collecting ducts?

Antidiuretic hormone (ADH).

How does Aldosterone influence reabsorption?

It is secreted by the adrenal cortex and causes sodium reabsorption in exchange for potassium or hydrogen.

What effect does vasoconstriction of the afferent arteriole have on the Glomerular Filtration Rate (GFR)?

It decreases glomerular pressure and decreases filtrate.

What effect does vasoconstriction of the efferent arteriole have on the GFR?

It increases pressure in the glomerulus and increases filtrate.

What are the three factors that control arteriolar constriction to regulate GFR?

1. Autoregulation (local diameter adjustment), 2. Sympathetic nervous system (increases vasoconstriction in both arterioles), 3. Renin (secreted when blood flow to afferent arteriole is reduced).

What is indicated by the presence of nitrites or leukocyte esterase in a urinalysis?

Evidence of infection (products of white blood cells).

Distinguish between 'Urge' and 'Stress' incontinence.

Urge incontinence is caused by detrusor instability and involves large volumes of urine, while Stress incontinence is caused by sphincter insufficiency, triggers (like coughing), and involves small volumes.

What is the most common origin of Urinary Tract Infections (UTIs)?

Mostly bacterial in origin, often occurring with urinary stasis.

What is Pyelonephritis?

Inflammation of the kidney parenchyma (upper urinary tract), most often occurring as a result of a lower UTI.

What are the chemical compositions of renal calculi (urolithiasis)?

Crystallization of excessive calcium and other salts such as struvite ($75\%$) and Uric acid ($25\%$).

How is 'renal colic' defined?

Pain caused by kidney stones that typically begins in the abdomen, radiates to the hypochondrium (flank pain), and comes in waves.

What are the characteristics of Pre-renal acute renal failure?

A sudden and severe drop in blood pressure (shock) or interruption of blood flow to the kidneys from severe injury or illness.

Contrast the onset and early appearance of Acute vs. Chronic renal failure.

Acute failure has a sudden onset with early signs of oliguria and increased serum urea; Chronic failure has a slow, insidious onset with early signs of polyuria with dilute urine, anemia, and fatigue.

At what GFR range is a patient classified under 'Stage 4: Severely Decreased Function'?

$15$ – $29\%$

Explain the role of 'Loop Diuretics' such as Furosemide.

They inhibit the $Na^+/K^+/2Cl^-$ cotransport in the ascending loop of Henle, resulting in retention of $Na^+$, $Cl^-$, and water in the tubule; they are the most efficacious diuretics.

What is the mechanism of peritoneal dialysis?

Dialysate is inserted into the peritoneal space where waste products cross semipermeable membranes from the capillaries into the dialysate, which is then drained.

What is an Arteriovenous (AV) fistula?

The connection of an artery and a vein, resulting in a vein expanded due to increased blood pressure, used to facilitate haemodialysis.