Renal and Urinary Tract Diseases Flashcards
Narrowing of at least one artery that supplies the kidney is known as?
Renal artery stenosis
In renal artery stenosis, what happens after blood flow and pressure into the kidneys get reduced?
Activates the renin-angiotensin system, BUT cannot raise pressure within the kidney due to the stenosis
What is the function of Juxtaglomerular (JG) cells?
- Produce renin when arteriole pressure decreases
- Increases blood pressure
- Rate-limiting step for renin-angiotensin system
What is the function of the macula densa?
When arteriole pressure increases, there is less Na+ and Cl- reabsorption. This causes release vasoactive compounds to constrict arterioles and decrease GFR
What are the consequences of elevated arteriole pressure? (4)
- Increased pressure
- Increased fluid secretion
- Increased GFR
- Decreased reabsorption
What is the function of ACE? Where is it expressed?
- Angiotensin-converting enzyme
- Converts angiotensin → angiotensin II (AngII)
- ~70-80% in lungs, 20% in kidneys
What is the function of AngII? (3)
- Potent vasoconstrictor that directly increases blood pressure
- Stimulates adrenal glands to release aldosterone
- Increased blood pressure shuts off renin release
What is the function of aldosterone in the renin-angiotensin system?
- Promote Na+ and water absorption in the kidney
- Increases blood volume, thereby increasing blood pressure
What are the consequences of renal artery stenosis?
- Reduced blood flow and pressure into the kidney
- High blood pressure (renal HTN)
What are the treatment options for renal artery stenosis? (2)
Administration of ACE inhibitors and/or stent placement
What is nephrosclerosis?
- Sclerosis of arterioles and small arteries within the kidneys
- Caused by, and a cause of, hypertension
What glomerular changes occur in nephrosclerosis? (3)
- Glomerular basement membrane (GBM) damage
- Collagen in in Bowman’s space
- Fibrosis around capsule
Nephrosclerosis can lead to _____ of the walls of blood vessels in the kidney
Hyalinization
Malignant HTN is a frequent cause of ____ in patients with systemic sclerosis
Renal failure
What are the symptoms of nephrosclerosis?
- Unresolved (malignant) HTN
- In diabetics, increased risk of renal failure
What type of endothelial damage occurs in nephrosclerosis? What are it’s consequences?
- Fibrinoid necrosis
- Hyperplastic arteriolitis
- Results in protein leakage and development of clots; renal ischemia
Glomerular damage can be secondary to what other diseases? (4)
- Lupus
- Diabetes Mellitus
- Amyloidosis
- Goodpasture Syndrome
Primary glomerular diseases are typically ______
Autoimmune
What are the autoimmune causes of glomerular damage? (2)
- Circulating antigen:antibody complexes deposit in filtaration membrane
- Antibodies reacting against components of the filtration membrane
Nephritic syndrome refers to?
- Glomerular inflammation
- Proliferative changes and leukocyte infiltration
Nephrotic syndrome refers to?
- Podocyte injury
- Structural and /or phsyiolochemical alterations
- Damage to glomerular membrane results in protein leakage
How does nephritic syndrome present clinically?
- Hematuria
- Oliguira with azotemia
- Proteinuria
- Hypertension
What is oliguria?
Significantly decreased urine production
What is azotemia?
Increased nitrogen containing compounds in the blood (BUN)
What are the most common causes of nephritic syndrome?
- Acute postinfectious glomerulonephritis
- Rapidly progressive glomerular nephritis (RPGN)
- Immunologically-mediated
Describe the cascade of events that occurs in nephrotic syndrome following damage to the glomerular capillary walls.
Massive proteinuria → depletes serum albumin → hypoalbuminemia → reduces osmotic pressure → generalized edema → compensatory aldosterone secretion → hyperlipidemia and lipiduria
What is membranous nephropathy? Cause?
- Diffuse thickening of capillary walls
- Caused by Ig deposits or self-antibodies
What is post-streptococcal glomerulonephritis?
- Acute proliferative glomerulonephritis
- Antibodies to streptococcal proteins will recognize glomerular proteins
- Causes nephritic syndrome
Goodpasture syndrome is described as?
Renal failure with pulmonary hemorrhage
What is the cause of Goodpasture syndrome?
- Anti-GBM in kidney (severe glomerular injury)
- Anti-GBM recognizes collagen IV in alveolar basement membrane
How does Goodpasture syndrome present clinically?
- Hemoptysis
- Hematuria
- Nephritic syndrome
- Potential nephrotic syndrome
What are the treatment options for Goodpasture syndrome? (2)
- Plasmapheresis to remove antibodies
- Immunosuppression
What is Crescentic Glomerulonephritis?
- Rapid loss of renal function (RPGN)
- Parietal cells fill urinary space
What is acute pyelonephritis?
- Tubulointerstitial nephritis
- Bacterial infection due to UTI
- Inflammation of interstitium and tubules
What drugs can induce tubulointerstitial nephritis?
- Penicillin and other antibiotics
- NSAIDS
If water ingestion exceeds urine excretion rate of _____ it leads to water intoxication
16 mL/min
What is the major symptom of water intoxication?
Swelling of CNS neurons, which leads to:
- Convulsions
- Coma
- Death
Acute kidney injury (AKI) is the most common cause of?
Acute renal failure
Acute renal failure is described as:
- Rapid reduction of renal function
- Urine output <400 mL/day (oliguiria to anuria)
How much urine do the kidneys normally produce per day?
1.5 L/day
50% of acute renal failure occurs _____
in patients hospitalized for other reasons
What are the potential causes of AKI?
- Ischemia
- Directy toxic injury
- Inflammation
- Urinary obstruction
How can AKI be treated?
- Prevention of further damage (address primary cause)
- Antibiotics to prevent secondary infection
- Diuretics to flush out the kidneys
- Dialysis
In AKI, is necrosis more typically found in the proximal or distal tubules?
Proximal tubules
Chronic kidney disease (CKD) is described as:
- Significantly decreased GFR and/or albuminuria for 3 months
- Irreversible loss of tubular cells
True or false. AKI can resolve through regeneration
True
What are some causes of chronic kidney disease (3)? Most chronic (***)?
- ***Diabetes mellitus
- Hypertension
- Glomerulonephritis
What are the treatment options for chronic kidney disease? (4)
- Treat underlying cause (HTN, diabetes, etc)
- Change in diet and lifestyle
- Dialysis
- Transplant
In general, altered kidney function affects (4):
- Sodium and potassium homeostasis
- Water balance
- Acid-base balance
- Urea excretion
Excess sodium expands intravascular volume, which increase reabsorption. This can lead to (2):
- Hypertension
- Congestive heart failure
Accumulation of nitrogenous waste products due to kidney failure is known as?
Uremia
What are the symptoms of Uremia? (4)
- Decreased appetite
- Fatigue
- Neurological symptoms (confusion or coma)
- Skin excretion (uremic frost)
Uremia can result from (3):
- Hypotension
- Dehydration
- Trauma (increased protein catabolism)
Why can CKD result in low calcium?
Kidneys are no longer able to activate vitamin D, which is essential for calcium and phosphate absorption
What is renal osteodystrophy?
- Lack of vitamin D reduces intestinal Ca2+ absorption
- Parathyroid hormone (PTH) increases osteoclast activity
What is the most common site for kidney stones?
Renal pelvis and calyces
What are some causes of kidney stones?
- Genetics
- Dehydration
- Dietary intake
- Hormonal imbalance (parathyroid tumor)
75% of kidney stones are composed of
Calcium oxalate and/or calcium phosphate
Besides calcium, what are some other types of kidney stones?
- Uric acid (<10%)
- Cystine (1%)
- Infection (15%)
What is hydronephrosis?
Expansion of the renal pelvis anc calyces due to obstruction downstream
How can kidney stones be treated?
- Pain management
- Prevent dehydration
- Shock waves (lithotripsy)
- Stent placement
- Prevent new stones (allopurinol inhibits purine catabolism to decrease uric acid)
- “Rollercoasters”
What is the main difference between acute and chronic cystitis?
- Acute: neutrophil infiltrates
- Chonric: mononuclear infiltrate (macrophages & T-cells)
What is cystitis?
Bladder inflammation
What are the different types of cystitis? (5)
- Bacterial
- Hemorrhagic
- Interstitial (b/w cells)
- Malakoplakia (defect in phagocytic cells)
- Polypoid
What are the most common species that cause cystitis (4)? Most common (***)?
- ***E. coli
- Proteus
- Klebsiella
- Enterobacter
What is the “symptom triad” of cystitis?
- Frequency (up to every 15-20 minutes)
- Lower abdominal pain
- Dysuria
