Renal, Urinary Systems, and Electrolytes Flashcards
(239 cards)
Hyperparathyroidism: Pathophysiology
How does primary hyperparathyroidism lead to osteoporosis?
Hypercalcemia and hypophosphotemia. Causing cortical thinning of the appendicular skeleton (eg, pectoral girdle, pelvic girdle, and limbs). Radiologically as subperiosteal erosions.
More advanced disease can present as osteitis fibrosa cystic, characterized by granular decalcification of the skull (“salt-and-pepper-skull), osteolytic cysts, and brown tumors.
Uworld: Physiology: Hypophosphatemia
What are some causes phosphate to decrease via internal redistribution?
3 points
- increased insulin secretion (refeeding malnourished)
- acute respiratory alkalosis (stimulate glycolysis)
- hungry bone syndrome (after parathyroidectomy)
Uworld: Physiology: Hypophosphatemia
What are some causes phosphate to decrease through decreased intestinal absorption?
3 points
- chronic poor intake
- aluminum or magnesium containing antacids (bind phosphate)
- steatorrhea or chronic diarrhea
Uworld: Physiology: Hypophosphatemia
What are some causes phosphate to decrease through increased urinary excretion?
4 points
- primary and secondary hyper-PTH
- vitamin D deficiency (decrease GI absorption, increased urinary excretion)
- primary renal phosphate wasting syndromes
- Fanconi syndrome
Pharmacology:
How does the drug Sevelamer help treat CKD?
- Prevents GI Phosphate absorption, decreasing the serum levels and decrease parathyroid over activation (secondary hyperparathyroidism)
- generally reserved for phosphate levels consistently greater than 5.5 mg/dL
- AE include GI upset, fatigue, and joint pain
Pathology:
What is the makes up the protein matrix of all urinary casts?
Tamm-Horsfall mucoprotein
Pathology:
What type of hypersensitivity is Goodpasture syndrome and type 1 rapidly progressive glomerulonephritis?
Type 2
Pathology:
What type of hypersensitivity is Post-streptococcal glomerulonephritis, type 2 RPGN, and membranous glomerulopathy?
Type 3
Pathology:
What are the causes and findings for epithelial cell casts?
Causes:
- Acute tubular necrosis
- ethylene glycol toxicity
- heavy-metal poisoning
- acute rejection of transplant graft
Findings:
- desquamated tubular cells in a protein matrix
Pathology:
What are the causes and findings for red blood cell casts?
Causes:
- Glomerulonephritis: IgA nephropathy, PSGN, and goodpasture syndrome
- Malignant HTN
- vasculitis
- renal ischemia
Findings:
- clumps of dysmorphic RBCs with blebs and buds indicate RBCs are of glomerular origin versus bladder origin (eg, bladder cancer)
Pathology:
What are the causes and findings for white blood cell casts?
Causes:
- pyelonephritis
- interstitial nephritis
- lupus nephritis
Findings:
- WBC casts indicate inflammation in renal interstitial tubules, and/or glomeruli
- WBCs in urine indicate lower UTI
Pathology:
What are the causes and findings for Hyaline casts?
Causes:
- often seen in normal urine
- pyelonephritis
Findings:
- glassy looking
- composed of Tamm-Horsfall protein
Pathology:
What are the causes and findings for granular casts?
Causes:
- ATN
- chronic renal failure
- nephrotic syndrome
Findings:
- derived from the breakdown of cellular causes, especially epithelial casts
Pathology:
What are the causes and findings for fatty casts?
Causes:
- nephrotic syndrome
Finding:
- fat droplets in hyaline matrix
- Maltese-cross configuration due to presence of cholesterol (under polarized light)
Pathology:
What conditions manifest with nephrotic syndrome?
6 points
- MCD
- FSGN
- Membranous glomerulopathy
- Membranoproliferative glomeronephritis
- Diabetic nephropathy
- Lupus Nephropathy
Pathology:
What conditions manifest with nephritic syndrome?
7 points
- acute proliferative glomerulonephritis (poststreptococcal/infectious)
- Rapidly progressive glomerulonephritis (crescentic)
- Anti-GBM disease Goodpasture syndrome
- MPGN
- IgA nephopathy (Berger disease)
- Hereditary nephritis (Alport syndrome)
- Lupus nephritis
Pathology:
What are the key findings of nephrotic syndrome?
- Massive proteinuria ( > 3.5 g/24h)
- Hypoalbuminemia (plasma albumin level < 3 g/dL)
- Edema
- Hyperlipidemia, urinary fatty casts, and hypercoagulation are also hallmarks
Pathology:
Thick GBM but no proliferation
membranous glomerulopathy
Pathology:
Thick GBM with hypercellular glomeruli?
membranoproliferative glomerulonephritis
Pathology:
How would you describe crescentic glomerulonephritis?
Proliferation of the parietal epithelial cell lining of Bowman capsule (forms a crescent)
Pathology:
Patients with nephrotic syndrome are at increased risk for what type of infections, why?
- Encapsulated bacterial infections (Staphylococci and pneumococci)
- loss of gamma-globulins
Pathology:
What is MCD usually preceded by?
Respiratory infections or routine immunization
Pathology:
What are some other names for MCD?
- lipoid nephrosis
- nil disease
- foot process disease
Pathology:
How would diagnose MCD?
Light microscopy:
- no obvious chances but note a lipoid appearance in the PCT
Electron Microscopy:
- podocyte effacement and increased lipoproteins in the PCTs
- * Definitive dx is made when there is diffused effacement