Function of Urinary System - 2

Question 1

Nephrosis

Answer 1

Lipoid nephrosis - 2-6 years old
Abnormality in glomerular capillaries and increased permeability that allow large amounts of plasma protein, to escape into filtrate
Hypoalbuminemia, decreased plasma osmotic pressure, subsequent generalized edema
Decreased blood volume increased aldosterone secretion leading to more edema
Signs and symptoms - Proteinuria, lipiduria and casts, frothy urine.
Weight gain and pallor
Ascites, pleural effusion

Question 2

Urinary tract obstruction - common causes

Answer 2

Prostatic hypertrophy, prostatic cancer, tumors, inflammation, scarring, stenosis, congenital defects, renal calculi

Question 3

Urolithiasis (calculi or kidney stones)

Answer 3

Calculi can develop anywhere in the urinary tract, small or large.
Form when there are excessive amounts of relatively insoluble salts in the filtrate and / or insufficient fluid intake
Cell debris from infection can also cause or add to
can lead to infection because they cause stasis or urine and irritate tissues
When located in kidney or ureter, may cause hydronephrosis with dilation of calyces and atrophy of renal tissue related to backpressure of urine.
75% are calcium salts, remainder uric acid
Calcium stones - hypercalcemia, perhaps due to a parathyroid tumor

Question 4

Signs and symptoms of kidney stones

Answer 4

Frequently asymptomatic
Sometimes flank pain occurs because of distention of renal capsule
Obstruction of ureter causes an attack of renal colic - intense spasms of pain in flank area radiating into the groin - vigorous contractions of ureter to force stone out.
Nausea
Vomiting
Cool moist skin
Rapid pulse
Treated with “extracorporeal shock-wave lithotripsy and laser lithotripsy”, drugs to dissolve stones.

Question 5

Hydronephrosis

Answer 5

Secondary problem
Complication of calculi and also tumors, scar tissue and untreated prostatic enlargement.
Interference with urine outflow, back pressure, backup in kidney causes necrosis because of compression of blood vessels.

Question 6

Tumors

Answer 6

Renal cell carcinoma (adenocarcinoma of the kidney) - primary tumor arising from the tubule epithelium more often in the renal cortex. Usually metastasizes before it is detected.
Signs and symptoms - hematuria, dull, aching flank pain, palpable mass, weight loss, anemia, erythrocytosis
Paraneoplastic syndromes such as hypercalcemia (increased PTH) or Cushing’s (increased adrenocorticotropic hormone) are common.
Usually detected after its metastasized.

Question 7

Bladder cancer

Answer 7

Malignant tumors usually arise from transitional epithelium lining the bladder, usually develops as multiple tumors, tends to recur.
Diagnosed by urine cytology
Metastasized through the blood into pelvic lymph nodes, liver and bone.
Signs: Hematuria, infection, dysuria
High incidence in those working with chemicals - dyes, rubber, aluminum, smoking, recurrent infection, heavy intake of analgesics.

Question 8

Nephrosclerosis

Answer 8

Vascular changes, similar to arteriosclerosis, in the kidney. Some changes occur normally with aging, excessive changes cause thickening and hardening of the walls of the arterioles and small arteries and narrowing or occlusion of the lumina of the blood vessels.
Reduce blood supply to kidney, causing ischemia and atrophy
Stimulate secretion of renin which increases blood pressure
Leads to renal failure

Question 9

Vesicoureteral reflux

Answer 9

Defective valve in bladder

Question 10

Agenesis

Answer 10

Developmental failure of one kidney to develop, asymptomatic

Question 11

Hypoplasia

Answer 11

Failure to develop to normal size, often unilateral

Question 12

Ectopic kidney

Answer 12

Kidney and its ureter are displaced out of normal position - ureter may become kinked

Question 13

Fusion

Answer 13

Two kidneys can fuse forming a single horseshoe - function usually normal

Question 14

Adult polycystic kidney

Answer 14

Genetic disease
Usually manifests at 40 years
Chronic renal failure, dialysis required
Multiple cysts develop in both kidneys are gradually expand, enlarging the kidneys, then compressing and destroying kidney tissue.

Question 15

Wilms’ Tumor (Nephroblastoma)

Answer 15

Rare tumor, occurs in children, associated with defects in tumor-suppressor genes, usually unilateral
Usually diagnosed between 3-4 years

Question 16

Acute Renal Failure

Answer 16

Kidneys may fail for many different reasons, either directly reduced blood flow into kidney or inflammation and necrosis of the tubules cause obstruction and back pressure, greatly reduced GFR and oliguria (reduced urine output) or anuria (no urine output).
Numerous causes:
Glomerulonephritis - reduces GFR
Severe prolonged circulatory shock or heart failure resulting in tubule necrosis - burns, crush injuries, sepsis
Nephrotoxins - drugs, chemicals, toxins cause tubule necrosis and obstruction of blood flow - includes NSAIDs, acetaminophen and aspirin.
Occasionally mechanical obstructions such as calculi, blood clots, tumors.

Question 17

Signs of Acute renal failure

Answer 17

Metabolic acidosis, hyperkalemia, elevated serum nitrogen - failure of kidneys to remove wastes.

Question 18

Chronic Renal Failure

Answer 18

Gradual irreversible destruction of kidneys over a long period of time, may result from chronic kidney disease.
Decreased reserve - 60% nephrons lost, decrease in GFR, remaining nephrons adapt and compensate
Renal insufficiency - Change in blood chemistry and manifestations - GFR is decreased to approximately 20% of normal, significant retention of wastes in the blood, tubule function decreased, excretion of large amounts of dilute urine, erythropoiesis decreases, patient elevated blood pressure.
Uremia - end-stage renal failure, 90% nephrons lost, fluid electrolytes and wastes are retained in body, oliguria or anuria develop, regular dialysis or kidney transplant.

Question 19

Early signs of chronic renal failure

Answer 19

Increased urinary output, frequency and nocturia
Anorexia, nausea, anemia, fatigue, unintended weight loss, exercise intolerance
Impaired cell function caused by increased wastes
High blood pressure
Complete kidney failure:
Oliguria (small amounts of urine)
Dry, pruritic, hyperpigmented skin, peripheral neuropathy, impotence, encephalopathy - lethargy, memory lapses, seizures), congestive heart failure, arrhythmias, hypocalcemia and osteoporosis, tetany, systemic infections

Question 20

Explain how the physical examination of a urine sample can give information to help diagnose a urinary disorder.

Answer 20

Normally, urine is clear, straw-colored, and has a mild odor.

If the urine is dark in color, it may indicate the presence of blood, excessive bilirubin, or highly concentrated urine. Cloudy urine may indicate the presence of blood cells, large amounts of protein, or bacteria/pus (indicating an infection). Unpleasant or unusual odor indicates possible infection or a metabolic condition that may be the result of dietary components or medication