16 The Urinary System and the Male Genital Tract Flashcards
Aims
Anatomy
Basic physiology
Introduction to the main diseases affecting the renal system and male genital tract
Overview
Urinary tract infections
Kidneys
Bladder
Prostate
Testis
Urinary Tract Infections
Very common disorder of the urinary tract
Risk factors include: Females>males Sexual intercourse Pregnancy Diabetes Urinary tract obstructions e.g. stones or catheters
Urinary Tract Infections
Bacteruria: bacteria in the urine, may be asymptomatic or symptomatic.
Urinary Tract Infection (UTI): the presence of pure growth of >10^5 organisms in fresh urine.
in urethra : Urethritis in bladder : Cystitis in prostate: Prostatitis in kidney : Pyelonephritis
E.coli is the most common causative organism (>70% of community UTIs).
Other organisms include: Staphylococcus, Proteus and Klebsiella
Urinary Tract Infections
cystitis:
frequency, dysuria, urgency, haematuria and suprapubic pain
pylonephritis:
high fever, rigors, vomiting, loin pain and tenderness
prostatitis:
flu like symptoms, few urinary symptoms and a swollen tender prostate on PR
Management
Drink plenty of fluids.
Urinate often (double voiding).
Antibiotics (trimethoprim usually first line treatment in uncomplicated UTIs).
Imaging – US in non-resolving UTIs, children, men and pyelonephritis.
Severe cases may require hospital admission specially pyelonephritis and in the elderly
Kidney Function
Maintinance of water, electrolyte and acid-base homeostasis.
Excretion of many toxic metabolic waste products (urea and creatinine).
Hormonal function
Renin – help control blood pressure
Erythropoietin- stimulates production of RBCs in the bone marrow and helps in the production of vitamin D.
Kidney Function
The functional unit is the nephron (consisting of a glomerulus and a renal tubule).
Filtration of most small molecules from the blood in the glomerulus.
Selective reabsorption in the renal tubule of most of the water and some molecules.
Maintenance of the acid-base balance.
Acute Renal Failure
A significant deterioration in renal function occurring over hours or days
There is a low urine volume (
Causes
Pre-renal
Hypoperfusion, sepsis
Renal
ATN damage to tubules due to ischaemia or nephrotoxins
Post-renal
Renal tract obstruction (eg stones, tumours)
Management
Find and treat the cause
Treat exacerbating factors ( hypovolaemia, sepsis.. etc).
Stop nephrotoxic drugs ( NSAIDs, ACE-I, gentamycin and Vancomycin)
May need renal replacement therapy (haemofiltration/dialysis)
Chronic Renal Failure
Classified into 5 stages depending on the glomerular filtration rate (GFR)
GFR is the volume of fluid filtered from the glomerular capillaries into the Bowman’s capsule per unit time
Symptoms usually occur by stage 4
Stage 1 = >90 Stage 2 = 60-89 Stage 3 = 30-59 Stage 4 = 15-29 Stage 5 =
Chronic Renal Failure Common Causes
Glomerulonephritis Diabetes Renovascular disease Hypertension Polycystic disease
Managed under nephrology team. Treat reversible causes. Avoid exacerbating factors, avoid nephrotoxic drugs.
May progress to renal replacement therapy
Glomerulonephritis
A group of disorders where there is damage to the glomerular filtration apparatus. This may cause a leak of protein or blood into the urine.
Usually there is a deposition of immune complexes in one part of the nephron
Stones
Crystal aggregates that form in the collecting ducts of the kidneys and can deposit anywhere in the renal tract.
Life time incidence 15%
Peak age 20-40 years.
Male: female = 3:1