Urinary Tract Flashcards
Glomeruli
Bundle of capillaries for filtering blood
Primary function of urinary tract
Formation and excretion of urine
- Ultrafiltration of blood in the nephrons of the kidneys
- Urine then enters renal collecting system
- Through ureters to urinary bladder
- Discharged through urethra
Nephron
Basic functional unit of the kindey
Contains glomeruli, tubules and collecting ducts
~90% of fluid is reabsorbed
Conserves water, balances pH and ionic composition of blood
Hormones that kidneys synthesize (2)
- Renin
2. Erythropoietin
Renin
Raises blood pressure
Erythropoietin
Stimulates RBC production in the bone marrow
Hormones that regulate kidney function (3)
- Antidiuretic hormone
- Arterial natriuretic factor
- Aldosterone
Imperative for normal kidney function
Antidiuretic hormone
Stimulates water uptake in the distal convoluted tubules
Arterial natriuretic hormone
Stimulates water loss
Aldosterone
Increases sodium reabsorption which increases body fluid volume
Juxtaglomerular apparatus
Senses pressure in distal tubule, and promotes production of renin
Developmental disorders (4)
Very common, mostly asymptomatic
- Renal agenesis
- Horseshoe kidney
- Polycystic kidney disease
- Multicystic renal dysplasia
Renal agenesis
Bilateral or unilaterial
No kidneys
Horseshoe kidney
Kidneys fuse at posterior section
Function usually not impaired
Accidental discovery
Polycystic kidney disease
Autosomal polycystic kidney disease - 85% due to mutation in polycystin-1
Kidneys lose function completely and need dialysis/donor (40-50yo)
Bilateral involvement, massive enlargement, almost complete parenchymal replacement by cysts, derived from blocked tubules
Cysts arise in nephron, epithelial lining, interstitial inflammation and fibrosis
Symptoms of autosomal dominant polycystic kidney disease
Hematuria, oliguria, flank pain
Cystic renal dysplasia
Sporadic, non-familial
Abnormal metanephric differentiation
Unilateral or bilateral kidney enlargement, multicystic
Immature ducts surrounded by undifferentiated mesenchyme
Often focal cartilage, abnormal lobar organization
Mostly associated with ureteropelvic obstruction, ureteral agenesis or atresia and other abnormalities of lower urinary tract
Local symptoms of kidney disease
Changes is urine volume - polyuria or oliguria
and composition - hematuria, glucosuria, pyuria
Pyuria
Pus formation in urine
Systemic symptoms of kidney disease
Fever
Malaise (infections)
Uremia
Uremia
Accumulation of various metabolites in the blood
Creatinine, uric acid, ammonia
Glomerular disease (4)
- Immunogenic diseases
- Metabolic
- Circulatory disturbances
- Multiple mechanisms
Glomerulonephritis
Immunogenic disease of glomerulus
Metabolic glomerular diseases (2)
- Diabetes
2. Amyloidosis
Circulatory disturbances causing glomerular diseases (3)
- Hypertension
- Atherosclerosis
- Disseminated intravascular coagulation
Symptoms of glomerular disease *** (4)
- Rapidly progressive glomerulonephritis
- Nephritic syndrome
- Nephrotic syndrome
- Isolated hematuria or proteinuria
Nephrotic syndrome (7)
- Increased glomerular permeability
- Nephrotic range proteinuria
- Hypoalbuminemia
- Edema
- Hyperlipidemia (lipiduria)
- Thrombo-embolism
- Infection
Nephritic syndrome (7)
- Hematuria
- RBC casts, dysmorphic/fragmented RBC in urine
- Oliguria
- Proteinuria
- Hypoalbuminemia
- Edema
- Hypertension
Crescentic glomerulonephritis
Immune related
Severe glomerular injury
Formation of fibrinous exudate inside Bowman’s capsule
Usually in patients with anti-glomerular basement membrane disease (Goodpasture’s syndrome)
Anuria and acute renal failure
Acute glomerulonephritis
Immune-mediated inflammation of the glomerulus, 1-2 weeks after acute infection
Nephritic syndrome
Glomeruli filled with inflammatory cells
Poststreptococcal Acute Glomerulonephritis by EM (5)
- Deposition of immune complexes in glomerular basement membrane
- Glomeruli appear hypercellular, with increased mesangial cells and inflammatory cells
- Compression of capillaries causing renin release
- BM damage leads to hypoalbumemia
- Peripheral edemia
Membranous nephropathy
Common cause of nephrotic syndrome in adults
Immune-mediated glomerulopathy
Thickening of BM secondary to massive deposition of immune complexes
Staining for Ig, C3 shows granular staining around capillary walls
Lipoid nephrosis
Minimal change disease
Most common nephrotic syndrome in children
Nephrotic syndrome with hyperlipidemia and lipiduria
Fusion of foot processes by electron microscopy
Chronic proliferative glomerulonephritic (4)
- IgA nephropathy
- Membranoproliferative GN
- Focal mesangial proliferative GN
- SLE
(no effective treatments except SLE)
Diabetic glomeruloscerlosis
Most prevalent metabolic disease affecting kidneys
Hyperglycemia causing changes in renal glomeruli, arterioles, interstitium
Thickening of BM and mesangial matrix (diffuse or nodular)
Proteinuria (10-20 years after onset)
Prone to bacterial infections, pyelonephritis
End-stage glomerulopathy (4)
- Chronic renal failure
- Symmetrically shrunken, fine surface granularity caused by loss of renal tubules
- Patients develop progressive uremia
- Replacement of glomeruli by collagen
Acute tubular necrosis
Sudden decrease in arterial pressure leads to acute hypoperfusion in the kidneys
Nephroangiosclerosis
Decreased blood flow due to renal artery artherosclerosis
Leading to ischemic glomerulosclerosis
Urinary stones (4)
- Calcium (75)
- Struvite (15)
- Uric acid (5)
- Cystine (1)
Ascending UTI
Bacteria reach urinary tract through the urethra
More common
Women more susceptible
Predisposing conditions: nodular prostatic hyperplasia, urolithiasis, bladder catheterization, pregnancy
Descending UTI
Bacteria reach urinary tract from the blood
Hematogenous infection
Usually preceded by sepsis or septic emboli
Acute pyelonephritis
Suppurative infection of the kidneys
Appears swollen, pale
Microabsesses
Chronic pyelonephritis
Develops from repeated bouts of acute pyelonephritis
Persistant infection leads to destruction of the renal parenchyma, affected kidneys become small and irregularly scarred
Acute cystitis
Congestion and mucosal hemorrhage
Mucosa may be ulcerated or covered with pus
Fever, pain, hematuria, pyuria
Chronic cystitis
Mucosa has considerable thickening, ulceration and hemorrhage
Cystitis
Inflammation of the bladder wall
Cystitis in elderly men
Complication of nodular prostatic hyperplasia
Cystitis in women
Bacteria cystitis may be associated with sexual intercourse and pregnancy
