Urinary Tract Flashcards
Hilum
Part of the kidney where the renal artery, vein and ureter enter
Primary function of urinary tract
Formation and excretion of urine
(ultra filtration of blood in the nephrons, urine enters the renal collecting system, through ureters to bladder, discharged through urethra)
3 basic components of the nephron
- Glomeruli
- Tubules
- Collecting ducts
2 hormones kidneys can SYNTHESIZE (and their functions)
- Renin: increase BP
2. Erythropoietin: stimulate RBC production in bone marrow
3 hormones kidney function can be REGULATED BY (and their functions)
- Antidiuretic hormone: stimulates water uptake in the distal convoluted tubules
- Arterial natriuretic factor: stimulates water loss
- Aldosterone: increase sodium reabsorption which increases body fluid volume
Where is: 1. ADH 2. ANF 3. Aldosterone synthesized?
- hypothalamus
- atrium of heart
- adrenal glands
Juxtaglomerular cells
Smooth muscle cells found in the wall of afferent arterioles
Secrete renin in response to decrease in BP
Renal agenesis
A developmental disorder
Missing a kidney (unilateral) or both kidneys (bilateral)
Horseshoe kidney
A developmental disorder
Kidneys have fused
Function usually isn’t impaired
Polycystic kidney disease
Developmental disorder
Autosomal dominant (adult)
They become dysfunctional and really large
Have to be on hemodialysis until they can get a transplant
2 types
Develop symptoms of renal failure by age of 40-50 years
Present with: hematuria, oliguira, and flank pain
Usually related to gene polycystin-1
2 types of Polycystic kidney disease
Gross: bilateral kidney involvement, massive enlargement (4kg), almost complete parenchymal replacement by cysts
Micro: cysts arise anywhere in nephron, epithelial lining, interstitial inflammation and fibrosis
Oliguria
Unable to produce urine
(Multi) Cystic renal dysplasia
cause, gross, histology, associated with
Sporadic, non-familial disorder due to an abnormaility in metanephric differentiation
Gross: can be uni or bilateral, kidneys enlarged and multicystic
Histology: immature ducts surrounded by undifferentiated mesenchyme often with focal cartilage, abnormal lobar organization
Most cases associated with ureteropelvic obstruction, ureteral agenesis or atresia, and other anomalies of lower UT
3 most common causes of abdominal masses in infants
Multicystic renal dysplasia
Wilms’ tumor
Neuroblastoma of the adrenals
Most important local symptoms of kidney disease (2)
- Changes in urine volume (polyuria or oliguria)
2. Changes in urine composition (hematuria, glucosuria, or pyuria = pus)
4 most important syndromes related to glomerular diseases
- acute renal failure
- nephritic syndrome
- nephrotic syndrome
- isolated hematuria/proteinuria
Nephrotic syndrome
High protein (>3 or 3.5g/day) Hypoalbuminemia Edema Hyperlididemia (and lipiduria)* Thrombo-embolism (losing anti-thrombin and plasminogen, platelet activation) Infection (loss of Igs) Not a lot of inflammatory proteins seen
Nephritic syndrome
Hematuria * RBC casts, dysmorphic/fragmented RBCs in urinary sediment Oliguria * Proteinuria Hypoalbuminemia Edema, generalized Hypertension A lot of inflammatory related changes
Crescentic GN
Severe glomerular injury accompanied by formation of a fibrinous exudate inside Bowman’s capsule
Typically occurs in patients with anti-glomerular basement membrane disease
Develip anuria and acute renal failure
Inflammatory cells form crescent shape
Very acute, and have to be able to recognize it fast
Acute GN
Immune-mediated inflammation of the glomerulus that occurs 1-2 weeks after acute infection (strep throat)
Present with generalized edema, proteinuria, hematuria, oliguria, and hypertension
In pediatric patients can get high BP
Glomeruli appear hypercellular with increased mesangial cells and inflammatory cells
Membranous Nephropathy
One of the most common causes of nephrotic syndrome in adults (25% of cases)
Immune-mediated glomerulopathy characteried by thickening of the basement membrane secondary to massive deposition of immune complexes
Lipoid nephrosis
Minimal change disease
Most common cause of nephrotic syndrome in children
Hyperlipidemia and lipiduria
Fusion of the foot processes of epithelial cells seen by EM
Diabetic Glomerulosclerosis
Most prevalent metabolic kidney disease
Hyperglycemia causes thickening of basement membrane
Proteinuria develops later
Prone to bacterial infections
End-Stage glomerulopathy
Chronic renal failure from immune, metabolic or circulatory diseases
Kidneys appear shrunken, with fine surface granularity from loss of tubules
Progressive uremia
4 most common forms of kidney stones
- Calcium stones (CaPO4 or Ca oxalate stones = 75%)
- Struvite stones (magnesium ammonium phosphate (or sulfate) = 15%)
- Uric acid stones (5%)
- Cystine stones (1%)
Ascending vs descending routes of renal infection
Ascending: bacteria reach the urinary tract through the urethra, more common
Descending: bacteria reach the urinary tract from the blood
Acute pyelonephritis
Infection
Kidney looks swollen and pale
Microabsecces may be visible in papillae and cortex
Chronic pyeonephritis
May develop from repeated bouts of acute pyelonephritis
Leads to destruction of parenchyma
Kidney becomes small and irregularly scarred
Acute cystitis
Congestion and mucosal hemorrhage
In severe cases, mucosa may be ulcerated or covered with pus
Patients present with fever, pain, hematuria, and pyuria
3 circulatory disturbances
- Acute tubular necrosis (sudden decrease in arterial pressure leads to acute hypoperfusion of the kidneys)
- Nephroangiosclerosis (decreased blood flow due to renal artery atherosclerosis, which leads to glomerulosclerosis)
- Hypertension
