Urinary System Flashcards
What are diuretics and how do they enhance urinary output?
chemicals that enhance urinary output by:
Inhibiting ADH (e.g., alcohol)
Inhibiting Na⁺ reabsorption, reducing H₂O reabsorption (e.g., caffeine, drugs for hypertension or edema)
Inhibiting the medullary gradient formation (loop diuretics)
Acting as osmotic diuretics, which are not reabsorbed, keeping water in the urine
What is urinalysis and what can it detect?
an examination of urine to detect signs of disease or illegal substances
How is renal function assessed?
Blood tests: Measure nitrogenous wastes in the blood
Urine tests: Required alongside blood tests to determine renal clearance
What is renal clearance, and why is it tested?
The rate at which a substance is removed from the plasma by the kidneys and excreted in urine.
Uses:
Determines Glomerular Filtration Rate (GFR).
Helps detect glomerular damage.
Monitors progression of renal disease.
What is Chronic Kidney Disease (CKD), and what are its effects?
Glomerular filtration rate < 60 ml/min for at least 3 months.
Effects:
Decreased filtrate formation.
Accumulation of nitrogenous wastes in the blood.
Blood pH becomes acidic.
Common Causes: Diabetes mellitus and hypertension
How is CKD severity classified based on GFR?
G1: ≥90 (Normal/High)
G2: 60-90 (Mildly decreased)
G3a: 45-59 (Mild to moderate decrease)
G3b: 30-44 (Moderate to severe decrease)
G4: 15-29 (Severely decreased)
G5: <15 (Kidney failure)
How is CKD severity classified based on albuminuria?
A1: Normal/mild increase (<30 mg/g)
A2: Moderate increase (30-299 mg/g)
A3: Severe increase (≥300 mg/g)
What is renal failure, and what are its effects?
GFR < 15 ml/min.
Causes:
Uremia: Ionic/hormonal imbalances, metabolic abnormalities, and toxic molecule accumulation.
Symptoms: Fatigue, anorexia, nausea, mental changes, cramps.
Treatment: Hemodialysis, Kidney transplant
What are the components of urine?
95% water and 5% solutes
Nitrogenous wastes:
Urea (from amino acid breakdown)
Uric acid (from nucleic acid metabolism).
Creatinine (metabolite of creatine phosphate).
What are some normal solutes found in urine?
Ions: Na⁺, K⁺, PO₄³⁻, SO₄²⁻, Ca²⁺, Mg²⁺, HCO₃⁻.
Note: Abnormally high concentrations of these or the presence of blood proteins, WBCs, or bile pigments may indicate pathology.
What do different urine colors indicate?
Clear: Normal, but cloudiness may indicate a UTI.
Pale to deep yellow: Normal due to urochrome/urobilin (pigment from hemoglobin breakdown).
Abnormal colors (pink, brown, smoky): May be caused by certain foods, bile pigments, blood, or drugs.
What factors influence urine odor?
Slightly aromatic when fresh
Ammonia odor develops as bacteria metabolize urea.
Odor changes can occur due to certain drugs or vegetables.
Diseases can alter smell:
Diabetes: Acetone smell in urine.
What are the normal pH and specific gravity ranges of urine?
pH: Slightly acidic (~6), but ranges from 4.5 to 8.0.
Lower pH: High-protein or whole-wheat diet.
Higher pH: Vegetarian diet, prolonged vomiting, UTIs.
Specific Gravity: 1.001 - 1.035 (higher than water due to solutes)
How does aging affect the urinary system?
Kidneys shrink, and nephrons decrease in size and number.
Tubule cells become less efficient.
GFR declines to half by age 80 (may be due to atherosclerosis of renal arteries)
Bladder shrinks, leading to:
Nocturia: Frequent urination at night.
Incontinence: Loss of bladder control.
What are some abnormal urinary constituents?
Glucose
Proteins
Ketone bodies
Haemoglobin
Bile pigments
Erythrocytes
Leukocytes
What is the possible cause and condition for the abnormal urinary constituent - glucose?
Condition- Glycosuria
Possible cause- Diabetes mellitus
What is the possible cause and condition for the abnormal urinary constituent - proteins?
Condition- Proteinuria/ Albuminuria
Possible cause- Excessive exertion, pregnancy, heart failure
What is the possible cause and condition for the abnormal urinary constituent - ketone bodies?
Condition- ketonuria
Possible cause- starvation, untreated diabetes mellitus
What is the possible cause and condition for the abnormal urinary constituent - haemoglobin?
Condition- haemoglobinuria
Possible cause- transfusion reaction, haemolytic anaemia, severe burns
What is the possible cause and condition for the abnormal urinary constituent - bile pigments?
Condition- Bilirubinuria
Possible cause- transfusion reaction, haemolytic anaemia, severe burns
What is the possible cause and condition for the abnormal urinary constituent - Erythrocytes
Condition- Hematuria
Possible causes- Bleeding urinary tract
What is the possible cause and condition for the abnormal urinary constituent - Leukocytes
Condition- Pyuria
Possible cause- Urinary tract infection
What are the key processes of urine formation in the nephron?
Filtration
Reabsorption
Secretion
Excretion