9- Dev of Urinary Tract, Obstruction and Prostate Flashcards
What is the order of the fetal kidney systems
Pronephros (week 4), Mesonephros (form trigone), Metanephros
What mesodermal layer does the kidney develop from
Intermediate
Where does the first kidney structure appear
Cervical region
What does the pronephros do
Makes duct from cervical region to cloaca and drives development of next developmental stage
What is the urogenital ridge
Intermediate mesoderm that gives rise to embryonic kidney and gonad.
Where does mesonephric tubule develop
Caudal to pronephric region
What is the embryonic kidney made of
Mesonephric tubules and mesonephric duct
Can this stage conserve water
No
Importance of mesonephros
Reproductive system in males. Also sprouts ureteric bud which induces development of definitive kidney.
What does the ureteric bud do
Induces development (by releasing growth factors) of undifferentiated intermediate mesoderm (metanephric blastema) to form mesonephros.
Collecting system is derived from
Ureteric bud
Excretory component is derived from
Intermediate mesoderm under influence of ureteric bud
Ascent of kidney
Caudal to cranial. Cross arterial fork of vessels from fetus to placenta. This occurs due to elogation of trunk and expansion of pelvic volume.
Vascularisation of ascending kidney
Vascularised from aorta at higher level. Sometimes accessory renal arteries are kept.
What can go wrong
Renal agenesis- bud doesn't interact effectively Migration awry Duplication defects Ectopic ureter- incontinence Cystic disease
Name 2 anomalies related to migration
Pelvic kidney
Horseshoe kidney
Why does duplication defects and ectopic urethral orifices occur
Splitting of bud
Ability to drive differentiation = more lobes or distal part of bud opens ectopically.
What 3 systems start by sharing common caudal opening
Repro, Urinary, GI
Is the cloaca open to outside
No there is cloacal membrane
What is the function of urorectal septum
Divide the GI from urinary and repro. Creates urogenital sinus. The cloacal membrane ruptures giving access to outside
Urogenital sinus becomes…
Superior part connects to umbilicus. Majority becomes bladder, inferior part develops into urethra.
Development with NO Y chromosome present
Mesonephric duct reaches urogenital sinus and ureteric bud sprouts from mesonephric duct. The sinus expands and duct regress. Bud connected directly to bladder = development of ureter and bladder from sinus.
Development with Y chromosome present
Duct reaches sinus. Bud sprouts from duct. Sinus expands. Bud and duct make independent opening in sinus. Duct becomes vas deferens and connects epididymis to urethra. Interaction between trigone of bladder and ducts = prostate develops.
Parts of male urethra
Pre-prostatic, prostatic, membranous, spongy.
Male urethra development
Genital tubercle elongates and genital folds fuse = spongy urethra.
What is required for genital folds to fuse
Androgens and responsive tissue.
What is hypospadias
Defect in fusion of urethral folds. Urethra opens onto ventral surface not the end of glans.
Growth factors and metanephric blastema
Release growth factors which cause uteric bud to form . This then release GF = reciprocal induction
What are main pathogens for acute prostatitis
Escherichia Coli. Staphylococcus. Chlamydia Trachomatis. Neisseria Gonorrhoeae.
Symptoms of acute prostatitis
Malaise, rigors, fever, passing urine difficulty, dysuria, perineal tenderness
Cause of chronic prostatitis
Chlamydia trachomatis.
Histological findings of chronic prostatitis
Fibrosis as a result of chronic inflammation
What is BPH and who is it common in
Common over 60
Non-neoplastic enlargement - can lead to obstruction
Cause of BPH
Unknow, maybe levels of testosterone
Symptoms of BPH
Enlarged prostate
Compresses prostatic urethra
Obstructive lower urinary tract symptoms- poor stream, dribble, frequency, nocturia
Findings of a rectal exam for BPH
Firm, smooth, rubbery
Risk of untreated BPH
Retention, overflow incontinence, bilateral upper tract obstruction, renal impairment - CKD
Treatment of BPH- drugs
Smooth muscle relaxers- alpha blockers (bladder neck and prostate)
Finasteride- prevents conversion of testosterone into more potent dihydrotestosterone.
Risk of obstruction
UTI- stasis
Reflux up ureter
Stone formation
Causes of renal retension
Calculi, pregnancy, tumours, drugs, surgery, strictures, BPH, neurogenic disorders (trauma- interferes with micturition pathway)
Symptoms of acute retention
Painful to void
Residual volume- 300-1500ml
Symptoms of chronic retention
Painless
Still void
Residual volume - 300-4000ml
Management of acute retension
Catheter History Exam Urine U&Es Treat causes- constipation
Management of chronic retension
Catheterise and measure residual History Exam Dip and U&Es Long term catheter plan
Low pressure vs high pressure
Normal renal function
No hydronephrosis
Bladder compliant but not emptying ? neuro problem
VS
Abnormal U&Es, hydronephrosis, renal scarring and risk of CKD development.
Post obstructive diuresis
Following resolution of retention Over diurese Worsening AKI as electrolytes and fluid excreted. Therefore loss of countercurrent in loop of henle because of back up = more water lost Monitor for 24 hrs post catheter. Treat with IV fluid and
Hydronephrosis
When bilateral when unilateral
Dilation of renal pelvis and calyces due to obstruction. Leads to increased pressure and blockage.
Bilateral- if lower urinary tract obstruction
Unilateral- if upper urinary tract obstruction
Problems with hydronephrosis
Progressive atrophy of kidney= increased hydrostatic pressure in Bowman’s capsule = GFR decreases = renal failure if bilateral.
Hydronephrosis VS hydroureter
Obstruction at pelviureteric junction vs ureter. Hydroureter develops into hydronephrosis.
How does hydroureter develop
Hydroureter develops from obstruction of bladder neck/urethra –> bladder distension with hypertrophy
Acute ureteric obstruction causes what pain
Renal colic- pain loin to groin radiating
Cause of acute ureteric obstruction
Calculus, clots, slough papilla
Can lead to pyelonephritis
What is Pyelonephritis
Infected, obstructed kidney.
Failure to treat pyonephrosis can lead to..
need to decompress as it may lead to death from sepsis and permanent loss of renal function.
Diagnosis of upper urinary tract obstruction
CT
USS
Diuretic renography: furosomide and then expect to see tract decline.
Drainage of upper urinary tract
nephrostomy (direct from kidney to outside)
JJ stend - helps bladder drain.
Urinary calculi affects mostly…
White, men
What causes increases in occurance
Dehydration
Where can stones/obstruction form
Pelviureteric junction, pelvic brim, vesicoureteric junction
Narrowest point
Gold standard for stone diagnosis
CT
Composition of calculi
Calcium oxalate (hypercalcemia, primary hyperparathyroidism)
Calcium phosphate- alkaline urine
Magnesium ammonium phosphate- urea splitting bacteria
Uric acid stone- gout and myeloproliferative disorders
Cystine stones- inherited cystinuria
Presentation of stones
Dull ache in loins
Radiates if ureteric stones due to peristalsis
Pale, sweaty, restless, nausea, vomiting
Strangury (urge to pass something that won’t)
Recurrent UTIs untreatable, haematuria, renal failure
Asymptomatic
Treatment of stone
Less than 5mm- wait
Larger than 5mm- extracorporeal shock waves, ureteroscopic destruction and removal, percutaneous nephrolithotomy, open surgical removal.
Prevention of stones
Hydration
Correct metabolic abnormalities- Ca and PTH
