Urinary System Disorders and Nephron Function

Study Notes

Analgesic Neuropathy
- Long-term use of painkillers, especially nonsteroidal anti-inflammatory drugs (NSAIDs)
- Ibuprofen and naproxen, particularly when combined with caffeine, are problematic
Chronic Renal Failure
- Progressive kidney disease
- Progression can be controlled by treating underlying causes like hypertension and high cholesterol
- End-stage renal failure requires dialysis or renal transplantation
Diabetes Insipidus
- Too little ADH production or the kidneys are insensitive to ADH
- Large urinary output, often leading to dehydration
- Risk of brain damage due to low sodium levels
Glomerulonephritis
- Inflammation of the glomerulus, damaging the filter
- Blood and blood cells appear in the urine (hematuria)
- Decreased waste product removal and electrolyte imbalance
Diabetic Nephropathy
- High blood glucose levels from diabetes damage the kidney's blood filtering part
- Damaged filter becomes leaky, leading to proteinuria and glycosuria
Kidney Stones (Renal Calculi/ Neprolithiasis/ Urolithiasis)
- Hard deposits of minerals and salts form in the kidneys
Polycystic Kidney Disease (PKD)
- Clusters of cysts develop primarily in the kidneys, causing gradual kidney damage

Pathophysiology: High blood glucose levels damage the glomerulus, making it leaky and causing proteinuria and glycosuria.
Glucose Reabsorption: Proximal convoluted tubule
Renal Threshold of Glucose: The blood glucose level at which glucose starts appearing in the urine. Approximate value is 180 mg/dL (10 mmol/L).

Definition: Hard deposits of minerals and salts, primarily calcium oxalate, calcium phosphate, uric acid, and struvite, that form in the kidneys.
Causes: Dehydration, high calcium intake, high uric acid levels, infections, and certain metabolic disorders.
Urine Formation Steps:
1. Filtration: Blood is filtered in the glomerulus, creating filtrate.
2. Reabsorption: Useful substances are reabsorbed back into the bloodstream from the filtrate.
3. Secretion: Waste products are secreted from the blood into the filtrate.
4. Excretion: The final urine is excreted from the body.

Diagnosis: Diabetes Insipidus based on low ADH levels, large amount of dilute urine despite water deprivation, symptoms of thirst and frequent urination.
ADH Action: ADH acts on the collecting ducts and distal convoluted tubule of the nephron.
ADH Function: ADH increases the permeability of the collecting ducts to water, allowing for more water reabsorption and the production of concentrated urine.