Urinary System Part 2

Question 1

Urinary Tract Obstruction

Answer 1

-A urinary tract obstruction is defined as a blockage of urine flow with the urinary tract
-The obstruction can be caused by an anatomic or functional defect
 Obstructive uropathy
Severity based on:
 -Location
 -Completeness
 -Involvement of one or both upper urinary tracts
 -Duration
 -Cause

Question 2

Urinary Tract Obstruction- Complete

Answer 2

• Hydroureter-dilation of ureter proximal to site of blockage
• Hydronephrosis-dilation of the renal pelvis and calyces proximal to site of blockage

Question 3

Urinary Tract Obstruction- Complete

Answer 3

Within 2 days:

• Tubulointerstitial fibrosis- deposition of excessive amounts extracellular matrix (collagen and other proteins)
• Apoptosis- excess cell destruction and death
• Partial function restored within 56-69 days if obstruction removed.

Question 4

Strategies for recovery renal function after urinary tract obstruction:

Answer 4

-Compensatory hypertrophy of healthy tissue
- Obligatory growth-Somatostatin

-Compensatory growth- unknown hormones   -Postobstructive diuresis   -Low bladder wall compliance  -Inability to accommodate urine at low pressures due to excessive deposition of extracellular matrix in bladder wall and detrusor muscle

Question 5

Urinary tract obstruction:

Answer 5

-Individuals at risk for hypertension
 -RAA cascade is elevated
-Individuals at risk for Urinary tract infections
 -Incomplete bladder empty
 -Urine turbulance in the urethra

Question 6

Upper Urinary tract obstruction: Kidney stones

Answer 6

• Calculi or urinary stones
   Masses of crystals, protein, or other substances that form within and may obstruct the urinary tract
  -Risk factors
   Gender, race, geographic location, seasonal factors, fluid intake, diet, and occupation
  -Kidney stones are classified according to the minerals comprising the stones

Question 7

Kidney Stones - 3 factors required:

Answer 7

1) Supersaturation of one or more salts
 -Presence of a salt in a higher concentration than the volume able to dissolve the salt
2) Precipitation of a salt from liquid to solid state
- Temperature and pH
3) Growth into a stone via crystallization or aggregation

Question 8

Temperature and pH

Answer 8

• Temperature usually constant so not usually a factor
• Acidic urine pH- increase risk uric acid stone
• Alkaline urine pH- increase risk of calcium phosphate stone

Question 9

Kidney Stones

Answer 9

-Other endogenous factors affecting stone formation
Crystal growth-inhibiting substances
Particle retention
Matrix- organic material contained in urinary calculus

- Stones
Calcium oxalate or calcium phosphate
Struvite stones
Cystinuric stones-genetic disorder amino acid metabolism
Uric acid stones
Indinavir- Rx protease inhibitor for HIV

Question 10

Calcium Oxalate or Calcium Phosphate Stones:

Answer 10

-80% of stones
-Idiopathic calcium urolithiasis (ICU)
 Unknown cause, but usually one or more of the following
 -Hypercalciuria
 -Hyperoxaluria
 -Hyperuricosuria
 -Hypocitraturia
 -Mild renal tubular
acidosis
 -Crystal growth
inhibitor deficiencies

Question 11

Hypercalcinuria:

Answer 11

Can be associated with
 -Intestinal hyper-
      absorption of 
      dietary calcium
 -Hyperthyroidism
 - Bone 
      demineralization 
      caused by 
      prolonged
      immobilization

Question 12

Struvite Stones

Answer 12

• Magnesium-ammonium-phosphate
• Large amounts of matrix
• Associated with Urinary tract infection

Question 13

Kidney Stones:

Answer 13

Manifestation- principle symptom
- Renal colic
Evaluation
- Stone analysis
- Intravenous 
     pyelogram
- Spiral abdominal CT Treatment
 -Stone removal

Question 14

Renal Colic

Answer 14

• Moderate to intense pain

- If stone in lower tract could have symptoms of urgency, frequent voiding, or urge incontinence

Question 15

Lower Urinary Tract Obstruction:

Answer 15

• Bladder neck dyssynergia
   –Smooth muscle urethrovesical junction fails to funnel during micturation and obstructs the bladder outlet
• Prostate enlargement

Question 16

Lower Urinary Tract Obstruction:

Answer 16

-Urethral stricture
--- Scar narrowing urethral lumen
--- Infection, surgery
 
-Severe pelvic organ prolapse
 --Cystocele blocks the bladder outlet

Question 17

Lower Urinary Tract Obstruction:

Answer 17

-Neurogenic bladder dysfunction
-Leads to urinary incontinence or retention

Pathophysiology
-Neurogenic detrusor overactivity
– Uncontrolled or premature contractions
 –Detrusor sphincter dyssynergia
-Obstruction- detrusor sphinctor dyssynergia
- Low bladder wall compliance

Question 18

Neurogenic Bladder Tumors:

Answer 18

-Renal tumors
 Renal adenomas
 Renal cell carcinoma
-Bladder tumors
 Papillary tumors
 Nonpapillary tumors
 Metastasis to lymph 
     nodes, liver, bone, 
     and lungs

Question 19

Urinary Tract Infection:

Answer 19

• UTI is inflammation of the urinary epithelium following invasion and colonization by some pathogen within the urinary tract
• Complicated UTI- comorbid to other disorders urinary tract
• Uncomplicated UTI – no other problems
• Persistent UTI- ongoing despite treatment

Question 20

Urinary Tract Infection:

Answer 20

-Most common pathogens
 Escherichia coli
 Staphylococcus 
     saprophyticus
 Enterobacter spp

Virulence of uropathogens-Strategies to survive
- Host defense 
      mechanisms
    -- Urine pH, urea, 
        periurethral 
        mucous-secreting 
       glands

Question 21

Urinary Tract Infection:

Answer 21

Cystitis
- Cystitis is an 
    inflammation of the bladder
-Manifestations
     Frequency, dysuria, urgency, and lower abdominal and/or suprapubic pain

Treatment
 -Antimicrobial therapy, increased fluid intake, avoidance of bladder irritants, and urinary analgesics

Question 22

Urinary Tract Infection:

Answer 22

-Pyelonephritis
—Acute pyelonephritis
 -Acute infection of the ureter, renal pelvis, and/or renal parenchyma
—Chronic pyelonephritis
 -Persistent or recurring
episodes of acute
pyelonephritis
 -Risk of chronic
pyelonephritis
increases in individuals
with renal infections
and some type of
obstructive pathologic
condition

Question 23

Glomerular Disorders:

Answer 23

-The glomerulopathies are disorders that directly affect the glomerulus
-Urinary sediment changes
- Nephrotic sediment
 (Proteinuria, lipiduria,
little or no hematuria)
 -Nephritic sediment
 (Hematuria, RBC casts,
White blood cells,
proteinuria)
 -Sediment of chronic
glomerular disease
 (Waxy casts, granular
casts, less prot. or hem).

Question 24

What is cast?

Answer 24

• “mass comprised of fibrous material, coagulated protein, or exudate that takes the shape of the region in which it has been molded, such as bronchial, renal, or intestinal structures and is usually found in urine or sputum.”
• McCance Glossary

Question 25

Glomerular Disorders

Answer 25

-Glomerular disease demonstrates a sudden or insidious onset of hypertension, edema, and an elevated blood urea nitrogen (BUN) - Decreased glomerular filtration rate  --Elevated plasma creatinine, urea, and reduced creatinine clearance -Glomerular damage causes a decreased glomerular membrane surface area, glomerular capillary blood flow, and blood hydrostatic pressure

Question 26

Glomerular Disorders:

Answer 26

- Increased glomerular capillary permeability and loss of negative ionic charge barrier result in passage of plasma proteins into the urine -Resulting hypoalbuminemia encourages plasma fluid to move into the interstitial spaces  --Edema

Question 27

Glomerular Disorders

Answer 27

``` -Glomerulonephritis  Inflammation of the glomerulus  -Immunologic abnormalities (most common)  -Drugs or toxins  -Vascular disorders  -Systemic diseases  - Viral causes ```

Question 28

Glomerulonephritis

Answer 28

-Mechanisms of injury  -Deposition of circulating soluble antigen-antibody complexes, often with complement fragments  -Formation of antibodies against the glomerular basement membrane  -Streptococcal release of neuramidase

Question 29

Glomerulonephritis- Types

Answer 29

- Acute poststreptococcal glomerulonephritis - IgA nephropathy (Berger disease) - Crescentic glomerulonephritis - Antiglomerular basement membrane disease (Goodpasture syndrome)-Chronic glomerulonephritis * cause, pathologic lesions, disease progression, clinical presentation

Question 30

Nephrotic Syndrome

Answer 30

-Excretion of 3.5 g or more of protein in the urine per day -The protein excretion is due to glomerular injury -Findings  Hypoalbuminemia, edema, hyperlipidemia, and lipiduria

Question 31

Nephrotic Syndrome

Answer 31

-Membranous glomerulonephritis  --Most common idiopathic nephrotic syndrome in whites; assoc. with hyperlipidemia and hyppercoaguability -Focal and segmental glomerulosclerosis  --Most common id Neur Syn in blacks.  Minimal change disease (lipoid nephrosis)  --Most common in children

Question 32

Nephrotic Syndrome- Pathophysiology

Answer 32

-Renal Dysfunction- Classifications  Renal insufficiency  < 10% function

Question 33

Renal Dysfunction: Classifications

Answer 33

Uremia  -Syndrome renal failure with elevated blood urea and creatinine, fatigue, nausea, vomit, pruritis, neurologic changes.  -Retention of nitrogenous toxic wastes, deficiency states, electrolyte disorders

Question 34

Renal Dysfunction: Classifications

Answer 34

Azotemia |  -Increased serum urea levels and creatinine levels, nitrogenous wastes

Question 35

Acute Renal Failure

Answer 35

-Acute- within hours -Prerenal acute renal failure  --Most common cause of ARF  --Caused by impaired renal blood flow  --GFR declines due to the decrease in filtration pressure

Question 36

Acute Renal Failure (ARF):

Answer 36

- Intrarenal acute renal failure  Acute tubular necrosis (ATN) is the most common cause of intrarenal renal failure  --Postischemic  --Nephrotoxic  - Postrenal acute renal failure  Occurs with urinary tract obstructions that affect the kidneys bilaterally

Question 37

Acute Renal Failure:

Answer 37

Oliguria: urine output less than 30ml/hr or less than 400ml/day

Question 38

Acute Renal Failure:

Answer 38

- initiation phase - maintenance phase - Recovery phase

Question 39

Chronic Renal failure:

Answer 39

-Chronic renal failure is the irreversible loss of renal function that affects nearly all organ systems -Progression  Reduced renal reserve  Renal insufficiency  Renal failure  End-stage renal disease

Question 40

Chronic Renal Failure: | Alterations in electrolyte and acid-base balance

Answer 40

- Creatinine and urea clearance - Sodium and water balance - Phosphate and calcium balance - Potassium balance - Acid-base balance

Question 41

Chronic Renal Failure:

Answer 41

- Skeletal and bone alterations - Cardiopulmonary system - Neural function - Endocrine and reproduction - Hematologic alterations

Question 42

Chronic Renal Failure:

Answer 42

- Immunologic - Gastrointestinal - Integument - Alterations in proteins, carbohydrates, and lipids