THE URINARY SYSTEM H.A MWAKYOMA, MD

Urinary System Kidneys Ureters Bladder Urethra Be sure to go over diagrams and other structures within the urinary system.

URINARY BLADDER

Anatomy-Kidney

Components of Glomerulus: Capillary basement membrane Mesangium Bowman capsule Cells Endothelial Epithelial Mesangial

Anatomy of Kidney

Anatomic Compartments Glomerulus Tubules Blood vessels Interstitium Collecting system (Callices & Pelvis)

Kidney Functions: Excretion metabolic waste/drugs. Water/fluid balance. Electrolyte balance. Acid-base balance. Blood pressure. Erythropoietin secretion.

Anatomy of Kidney Glomerulus Loop of Henley PCT, DCT, CT Note the positions of Glomerulus Loop of Henley PCT, DCT, CT Cortex, Medulla, Pelvis.

JGA GFR  Renin Angiotensin Blood Pressure

Filtration Membrane:

Normal Kidney:

Pathology definitions Oliguria – a decrease in the amount of urine that is being passed. Polyuria – too much urine is being excreted Anuria – total suppression of urine formation and secretion Retention – the bladder does not release urine Hematuria – blood in the urine Uremia – toxic wastes in the blood Cystitis – inflammation of bladder Pyelitis – inflammation of the renal pelvis. Dysuria – painful urination

Kidney Diseases Developmental disorders Glomerular diseases Tubulo-interstitial diseases Urinary stones Obstructive uropathy Tumors

Developmental disorders

Congenital Anomalies: Agenesis – Potter syndrome Ectopia Fusion Dysplasia Simple cysts Polycystic kidney disease

Renal agenesis (Solitary kidney) The total failure of a kidney to develop. Results from a failure of the embryonic renal bud or renal vascular system to form. Usually only occurs unilaterally

Bilateral renal agenesis

Unilateral renal ageneasis

Renal agenesis

Supernumerary kidney A third kidney that is usually small and rudimentary and possesses a separate pelvis, ureter, and blood supply

Partially fused supernumerary kidney with bifid ureter

Hypoplaisa (Hypoplastic kidney) A kidney that is less developed than normal. It is often called a miniature kidney

Hypoplastic kidney with renal dysplasia

Renal Ectopia A misplaced kidney that are usually found in the pelvis and associated with a short ureter. The short ureter is the key factor to rule out Nephroptosis. pg143

Anomalies of rotation, position and fusion Mal-rotation One or both kidneys may produce a bizarre appearance of the renal parenchyma, calyces, and pelvis that suggest a pathological condition when in reality the kidney is normal

Anomalies of rotation, position and fusion Nephroptosis The kidney falls down into the pelvis when a person stands up due to the pull of gravity Also called “floating kidney” or ectopic kidney

Crossed Ectopy One kidney lies either partially or completely across the midline and is fused with the other kidney at the lower pole.

Horseshoe kidney Both kidneys are joined at their lower poles across the midline of the body. Stones are more frequent The most common fusion anomalies

Horse Shoe Kidney

Horseshoe Kidney Situated usually in front of fouth lumbar vertebra Fused lower poles common Ureters angulated Infection Nephrolithiasis Fixed mass below umbilicus

Complete Fusion Both of the kidneys are fused together in a single irregular mass which has no resemblance to a renal structure.

Polycystic kidney disease Autosomal dominant (adult) (1:1,000) Autosomal recessive (infantile (1:30,000) Medullary cystic disease complex (1:10,000) Medullary sponge kidney Acquired cystic renal disease

Autosomal Dominant PKD Common kidney disease (1:1,000) ADPKD-1 gene (polycystin) mutation 85% Bilaterally enlarged kidneys (>3,000g) Symptoms appear in adult life Renal failure 5-10 years thereafter

ADPKD:

ADPKD:

ADPKD Associated Conditions Liver cysts (30%) Splenic cysts (10%) Pancreatic cysts (5%) Cerebral aneurysms (20%) Diverticulosis coli

Congenital cystic kidneys – polycystic kidneys Hereditary Autosomal dominant trait Not usually detectable until the second or third decades of life and never manifests before the age of 30 Irregular upper quadrant mass Loin pain Haematuria Infection Hypertension Uraemia CT image : multiple cysts in both kidneys

URETERS Duplication of a ureter The ureters usually join before they reach the bladder Less commonly the ureters open indepedently into the bladder Congenital megaureter

Double Ureter:

Ureteroceles Cyst like dilations of a ureter near its opening into the bladder. Radiographically it has the classic “cobra head” appearance. Like a diverticula only it goes into the bladder not out from it. When the bladder is full, it decrease the size of the ureterocele due to an increase in the pressure in the bladder. May cause obstruction if large enough.

URINARY BLADDER

Congenital defects of the bladder Ectopia vesicae – exstrophy of the bladder Easily recognised at birth Umbilicus absent, protruding due to the intraabdominal pressure In addition epispadias Mons and clitoris bifid In the neonate the bladder should be covered with Saran Wrap or clingfilm to prevent trauma to the delicate mucosa

Ectopia vesicae – exstrophy of the bladder

Exstrophy of the bladder

A case of ectopia vesica with absent pelvic bone and herniated caecum

Diverticula The bladder or ureters are common areas for diverticula (out pouching of the wall). Best seen on a retrograde ureogram Because urine can stay in these areas for a long period of time, infections or irritations may occur.

bladder. Bladder Diverticulum

Congenital abnormalities of the urethra and penis Meatal stenosis Congenital stricture Congenital valves Hypospadias epispadias

Meatus Congenital stenosis of the external urethral meatus – normally the narrowest part of the male urethra Associated with phimosis – at times pin hole meatus Back pressure effects Spraying, dribbling

Congenital Urethral Stricture Rare

Congenital valves of the posterior urethra Folds of urothelium Obstuction in boys Within prostatic urethra Catheter will pass easily Micturating cystourethrogram Pass catheter

Epispadias and Hypospadias Hypospadias: congenital defect in which the urinary meatus is located on the lower or underside of the shaft Epispadias: congenital defect in which the urinary meatus is located on the upper side of the penile shaft; less common than hypospadias

Epispadias and Hypospadias Clinical manifestations Ventral or dorsal placement of the urethral opening Altered urinary stream Chordee Diagnostic evaluation Based on physical examination

Hypospadias Most common urethral abnormality Glandular hypospadias Coronal hypospadias Penile and penoscrotal hypospadias Perineal hypospadias Avoid circumcision

Normal External Urethral Meatus

Hypospadias types

Hypospadias

Phimosis At birth foreskin adherent to the surface of the glans penis Separate spontaneously with time Can wait for 4 years to separate Gentle retraction at bath permitted Forcible retractions injure

Phimosis

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